Mostly because the "Is a radar detector worth it?" thread keeps going and going and going, and also partly because there are so many different opinions out there, I decided to create an informational RADAR thread. I really have no idea how it will progress (if any at all) or how it will end, but here goes:

First, a little about me. I've been a police officer for over 10 years, all of it as a street patrol officer. I've been a police RADAR instructor for over 6 years and have received about 60 hours of instruction in police RADAR operation and instructor school (teaching other police officers about police RADAR).

RADAR is an acronym for RAdio Detection And Ranging. I usually use capital letters whenver I write the word RADAR but it gets tiresome. So for here on out it's gonna be radar in lowercase.

I'm not really going to be proceeding in any sort of order. But I wanted to start with a little about the MAIN differences between radar detectors and laser detectors and their effectiveness. Other topics will come later assuming anyone is interested. Questions are more than welcome.

Think of a police radar beam as a flashlight beam - shaped like a cone. The end of the flashlight (or a police radar gun) at the lense might be a few inches wide. As the light (or radar beam) leaves the flashlight it gets wider and wider the farther it goes. Radar beams are infinite, meaning they will travel indefinitely until they are reflected, refracted or absorbed. Reflected as in off of a hard, reflective surface - refracted as in bent like through water or glass - and absorbed as in by the ground or other loose surface. X band radar has a beam width of 18 degrees, K band is 12 degrees and Ka band is 10 degrees. Think of being able to adjust the flashlight's beam from flood to spot - but even Ka band at 10 degrees is still pretty wide, so imagine you can't really adjust the flashlight to a spot, but rather it's adjustable from a really wide flood pattern to a not as wide but still pretty wide flood pattern. At night in your back yard when you point your flashlight into the darkness it will illuminate more and more the wider you adjust the beam. If you had several of your friends standing in the yard spaced out at regular intervals with light detectors (or radar detectors) and you pointed your flashlight at them (or radar gun), their detectors would go off as the light hit them. The wider the beam, the more you could see with your light and the more detectors would go off as the light (or radar) would shine on them. Of course, as I mentioned, radar beams are infinite which means that the beam might bounch off of a tree in your yard, a fence, and so on and might set off a few other detectors in the general vicinity even through they're not in the direct line of sight. **It gets more complicated than this for several reasons, but you get the general idea**

Example. A police officer using a conventional Ka band radar gun with a 10 degree beam width will be projecting a conical shaped radar beam ahead of him that will be about 35 feet wide (about the width of small city street) at a distance of 200 feet. At 1,000 feet, that same beam will be about 175 feet wide. A portion of that beam will be reflected off of a suspected speeding vehicle and returned to the radar gun to calculate its speed. The rest of the beam will shoot past that car as well as bounce around for a while and set off radar detectors in its path (to varying degrees depending on the quality of the radar detector). This is why radar detectors are worthwhile. They can tell you when a police officer is radaring other cars in your area - not necessarily you - and this will give you time to slow down before YOU are the one being radared. If an officer is patient and is laying in wait for you to come speeding down the street and turns the radar on at the last minute you are absolutely screwed because you can't possibly slow down fast enough to avoid having your speed measured.

Police laser radar (LIDAR) beams are much, much, MUCH narrower. Think of being able to adjust that flashlight beam I talked about earlier to a VERY finely focused spot light. Lidar has a beam width of around .17 degrees. This means that at 200 feet, that beam is only about 6 inches wide (about half as wide as your license plate). Even at 1,000 feet, that beam is only going to be about 3 feet wide (less than half the width of most cars). This is why the police can select a specific car out of a whole pack of cars when using lidar. Most lidar guns also have some sort of scope (like a rifle) with crosshairs to assist the operator in showing him/her exactly which car they're reading. And since this lidar beam is so narrow, most of it is directed straight back to the lidar gun rather than being scattered around and setting off a whole slew of laser radar detectors. Instead, most likely the only detector going off is the one that's just been targeted and - you guessed it - it's too late to slow down.

Well that's my two cents on the differences between police radar and lidar beams and why laser radar detectors are much less effective at helping you avoid speeding tickets than conventional radar detectors.

Tony

 

Awesome post, Tony! I learned alot from this.

 

LOL! Probably not as much as I've learned from all your insane projects lately!!! But thanks just the same!

Tony

 

Great info Tony...

 

Great post, made things really simple. Another reason laser detection is so much harder is because scattered/stray IR radiation is attenuated almost immediately by surrounding stuff (road, cars, trees, etc.). (Ie. your light won't really bounce around like the radar signal will).

How many Lidar gun manufacturers are there? (one? dozens?)
Do you know what wavelengths Lidar operates at?

-Tom

 

Great post Tony. I def learned as well.

 

I am NOT a certified Lidar instructor. However, I do know the basics and I can look up what I don't know.

Lidar waves are are approximately 904 - 905 nanometers (nm). A nanometer is one billionth of a meter. Lidar operates at a frequency of 330 terahertz (THz).

A wave is a propogation of a signal in space. Imagine dropping a pebble in some water. The waves will ripple away from the pebble at a regular interval. Think of a radar or lidar gun as propogating waves in a three dimensional cone wherever you point it. Obviously these waves are invisible. If you were to somehow measure the crests (the high parts) of the waves caused by that pebble you just dropped they might be an inch or two apart. Lidar waves by contrast would only be 904 - 905 billionths of a meter. (read: pretty small)

Imagine you were able to count the number of waves that went by you on the water after the pebble was dropped. If you had a stopwatch and could count the number of waves passing by in exactly one second, you would be measuring the wave's frequency. A hertz is a measurement of frequency. One hertz would equal one wave per second, or one cycle per second (cycle meaning wave crest to wave crest). Lidar transmits at 330 THz (terahertz) or in other words, 330 trillion hertz, or 330 trillion waves per second.

I'm not sure how many manufacturers there are. I've heard of LTI (Laser Technology Inc), Lidar, Stalker, Kustom Signals. I'm sure there are more.

Tony

 

Very good factual writeup on how handheld radar functions Tony.

 

Quick question for you Tony. In the past ive never had problems with LASER getting me tickets. But I recently got one for 75 in a 55. Only difference from the other times was that I have my Front license plate back on. Does that make a huge difference? I ask this mainly because I have a few road trips coming up and id rather take it off, since I only need to worry about my local PD handing out tickets for not having a front plate. Now the only other reflective parts on my car are the fog lights and the bumper lights. Headlights are 90% black, so it wont make it easy. Any input?

Other question. Do you have any information on the instant-on K band? They've started to use this lately in my area, but Ive only seen it in use when the patrol car was in motion. Kind of worries me since its almost like using Laser while driving.

 

BlueC,

From my understanding and research in RADAR and LIDAR, when an officer uses a LIDAR gun to aim at you, the best reading he can get is your license plate because its flat and reflective. Now, he can also get your headlights,and windshield too even if he can't target your plate. I hope I'm giving you correct information but Tony or others can clarify.

Andy

 

Police are trained to aim thier lidar guns at your license plate. Since it's perfectly flat and reflective not only does it provide a good "taget" but it also returns the signal most effectively. I can't attribute you getting or not getting tickets based soley on the absence of your front plate, but it certainly makes it easier to acquire a reading on your vehicle. If an officer doesn't get a speed reading because you don't have a front plate, it will only delay him from getting one because your car itself will also provide an adequate reflective surface to return a speed reading as well - but not as effective as a license plate. I suppose this MIGHT give you a little extra time to slow down if your detector goes off. Your car's color, size, arodynamic composition etc. will also have an effect. Of course, if you drive a semi truck with a huge, flat cab out front then not having a license plate won't make much difference, see?

Of course, most states require you to have a front license plate for the obvious reason of being able to identify your car by having both one on the front and rear of your car. So if you dont' have a front license plate and your state requires it, then you face the chances of being pulled over for it.

See above. Did that answer you question? Everything on your car will reflect a lidar or radar beam. All the officer needs is a portion of that beam to be returned to get a speed reading. Obviously the more stealth the car the more the beam is directed away from the radar/lidar gun. I've heard that nose bras can also be effective at absorbing radar/lidar. I don't know how much.

Instant on is old, old technology. K band has been around for a long time as well. K band is not exclusive to either moving or stationary radar and can be used for both. All instant on means is that the radar gun in turned on ready to go at a moment's notice, but it is not emitting any sort of radar beam. By flipping a switch or pushing a button (the RF hold, or "Radio Frequency" hold button) the beam is transmitted as soon as the button is depressed. Since radar beams travel at the speed of light (about 186,000 miles per second) it's quite effective at defeating ANY radar detector unless the officer has the gun on all the time or is radaring cars ahead of you.

Your comparison of moving K-band radar and lidar is not correct though. The benefits of lidar is the ability to select an individual car out of a group of cars. Conventional radar is not capable of doing this regardless of whether it's stationary or moving, or X, K, or Ka band.

I will address stationary vs. moving mode radar operation later.

Tony

 

Yes Andy, that is basically correct.

Tony

 

can other radars affect the speed readings? say for example there's a speed trap area, and i usually pick up two or 3 Ka bands...will officer A's reading be off if it picks up another echo from officer B's gun?

just curious

 

No. No matter how many radar guns are in operation in a given area they will not interfere with each other. A car moving at 35 mph is a car moving at 35 mph and no matter how many radar guns are aimed at it, regardless of band, they will not throw each other off.

It's a logical assumption that lidar is no different, but I'm not totally committed to saying so without any doubt, although I'm fairly certain.

Tony

 

Back in 1842 an Austrian physicist named Christian Johann Doppler developed a theory based on sound waves that basically said, "The frequency of a wave is relative to the motion between the source and the observer". This theory is known as the Doppler principle. It can be simply illustrated as the way a train whistle sounds higer pitched as it approaches you and then decreases in pitch after is passes. Through experimentation, it was found that the same principle applies to other waves, such as radio and light waves.

Police radar uses radio waves. Remember the acronym RADAR? RAdio Detection and Ranging. During WWII, we developed radar to track enemy aircraft. The frequencies the military used were top secret so they used letters to distinguish the different frequencies, such as X and K-band. This sort of radar was able to detect range, speed, and direction. Police radar detects MOTION only, not direction or range. A police radar gun can only tell you how fast a car is moving, not how far away it is or what direction it is moving.

As the train is approaching you the sound of its whistle is higher because the sound waves are compressed, which raises the frequency and thus makes it sound higher in pitch. After the train passes, the sound waves are stretched, which lowers the frequency and thus makes it sound lower it pitch.

This is the way police radar measures speed, only it uses radio waves, not sound waves.

The radar gun emits radio waves at a certain frequency. For X band, this happens to be 10.525 GHz (gigahertz - or one billion hertz - or one billion cycles per second). That's 10,525,000,000 hertz (ten billion five hundred twenty five million Hz). It's in the microwave spectrum. K band is 24.15 Ghz and Ka band can be anywhere between 33.4 and 36 GHz.

This beam of radio waves at a certain frequency transmits out of the radar gun at the speed of light, over 186,000 miles per second (or close to seven hundred million miles per hour). This beam then strikes a moving target (a vehicle) and then reflects back to the radar. What the radar does is it looks for a difference in frequency between the transmitted signal and the received signal. This difference in the transmitted and received frequency is called the doppler frequency or doppler shift. If you point a radar gun at a parked car, the transmitted signal is reflected back at the same exact frequency as it was sent out and the radar does not detect any motion so it therefore doesn't display a speed. However, if you point the radar gun at a car moving towards you, the reflected waves off of the approaching car will be compressed (higher in frequency) and the radar will calculate the difference in frequency as speed. If you point the radar gun at a car moving away from you, the reflected waves off of the receeding car will be stretched (lower in frequeny) and the radar will once again calculate the difference in frequency as speed.

If a K band radar gun transmits its beam at the frequency of 24.15 GHz at a parked car, the radar waves will bounce back at 24.15 GHz and the radar will just sit there with a blank screen. If a car is approaching the radar gun at lets say 50 mph, then the radar waves will be compressed and return a frequency that will be about 3,601 Hz higher than the transmitted frequency. So the original transmitted frequency of 24,150,000,000 Hz (twenty four billion one hundred fifty million Hz) will be returned at the slightly higher frequency of 24,150,003,601 Hz. Why does 50 mph translate to 3,601 Hz? I'm glad you asked. K-band radar has a doppler shift of 72.023 Hz for every 1 mph. So 50 multiplied by 72.023 is about 3,601. If for example the same radar gun was pointed at a car moving away from the radar at 50 mph, the waves would be stretched and you would get a lower returned frequency of 24,149,996,399 Hz (3,601 Hz lower).

If the radar gun in the above example transmitted it's beam at 24.15 GHz at a moving car and the returned frequency was 24,149,994,238 Hz, what was the car's speed? Was the car approaching or receeding? (answer below)

In short, the radar gun transmits a microwave at a very specific frequency. These waves are reflected off of moving objects and returned back to the radar. As objects are moving towards the radar, the waves are compressed and the returned frequency is higher. As objects are moving away from the radar, the waves are stretched and the returned frequency is lower. The difference between the transmitted and the returned frequencies is what the radar uses to calculate speed.

(answer to above question: 80 mph receeding car)

Tony

 

this is some good reading. thanks for all the info Tony

 

Do you know if all manufacturers use the same wavelength?

-Tom

 

No, I do not know.

Tony

 

I used to drive with a detector, alot of times I got false readings, can you explain this Tony? Also what is the deal with some cops that drive with the radar constantly on? I don't use mine because I'm not a speeder as most people define it, also TN cops are so lax (knock on wood) you are good in most areas if you are 10mph and under. Detectors work ok if they are trapping but mine hasn't had to save me yet. My boss has the phaser and he still got a ticket because of the angle the cop beamed him at. What is the mindset of a cop not showing you the speed he got you at? Any rogue cop could say you were speeding and not have an accurate reading could be lying. Thanks for any info Tony.

 

Good info Tony. It's always nice to enlighten members on information you have.

I knew most of it from my dad, who recently retired from a fairly large PD as a certified instructor in: radar, lidar and the operation of photo radar vans.

One thing I can say is that lidar is a bit tricky to use at first and usually takes a couple of tries to get a good reading. I have used a lidar gun before and for me (inexperienced) it took several tries to get a good speed reading. A lot of cars without much of a flat surface (say a 90s firebird or a vette) are very difficult to get a reading on, except the front plate. A good source other than the plate is usually the headlight. Someone with experience still can take a couple of tries to get a good reading.

I also did several ride-a-longs with Washington State troopers using "instant-on" radar, which is absolutely devastating on 2 lane highways. The trooper can drive behind another vehicle and get a good reading in just seconds on a car coming in the opposite direction. IMO, this is actually better than lidar, because there is less chance for the oncoming driver to see the officer/be warned by a detector. The only difficulty is in the officer turning around to make the stop. It's actually fun as a passenger! LT-1 Caprices are a lot quicker than a lot of people think, but the Crown Vics are not quite as fun.

If this makes a difference to any of you, I don't use a radar detector. I generally drive over the speed limit, but I definitely try to drive at a speed that is appropriate for the conditions. I have had one photo radar ticket (kind of a BS one) and that's it and I have driven well over 500k miles since I got my license, much of that on the roadways of Washington state, Oregon and Idaho.

 

The detector detects microwaves, and there's plently of those floating around in space. Neon signs, automatic doors, etc. It can also pick up harmonics, which are multiples of those certain frequencies. The more money you spend on a good quality detector, the better it is of rejecting those false signals.

I'm not sure why. A coworker of mine does exactly that. In fact, she'll even leave the radar on pretty much every time she gets out of the car.

The Phaser is a piece of junk. He still got a ticket because it doesn't work period.

We are NOT required to lock a speed reading into the radar. We are also not required to show the radar to someone when they ask, regardless of whether we locked it in or not. If I lock a speed in and someone asks to see it, I'll most likely show them. It should interest you to know that looking at a locked speed reading is meaningless. I could use a tuning fork and lock the speed reading in, or radar any speeding car and lock their speed in, or just drive the patrol car at the speed I wanted and lock that speed in. The fact that I have a flashing number displayed on my radar is meaningless - there's no way for a motorist to know that the displayed speed came from their car and not someone or something else. Heck, if I wanted to lock an "86" reading into my radar at the beginning of my shift I could drive around all day and pull people over for doing 86 mph! I've always wondered why people got satisfaction from looking at the radar - but I always try to accomodate them. I mean, after all, I've had a few speeding tickets during my driving career - I know how it feels & I try to have empathy.

Tony

 

nice write up and thanks for the information. It definitely shedded some light on stuff I was unfamiliar with about radar detectors.

 

Tony,
One question I have to ask. I was quickly going through some of the radar threads a while ago and stumbled on a question but didn't know who to ask until now. The radar guns out there now, K/Ka band,(i got this off one of their sites) that hang outside of the cop's window, it is said that the detector can tell which lane the person is speeding in. Is this true? I thought that when an officer gets a reading that is over the limit set on his gun, it was up to him/her to determine who is speeding.

Just curious.
Thanks

Andy

 

I'm not sure what it meant by being able to tell which lane someone is speeding in. With radar, yes, it is up to the officer to determine which car is giving the specific radar reading. There might be more to what you read than that, but I'd had to read it myself to provide more input.

Tony

 

One thing about Lidar, does the surface have to be reflective in order for the gun to get a reading? i.e. License Plate.

Is it easier or harder to get readings at night with the headlights and foglights on?

 

Most any flat surface will be reflective, regardless if it's a license plate. I think I already answered part of this question in one of my previous posts. Let me know if you still have a question and I'll try to clarify.

I've heard that the more lighting coming from your car means it takes longer to get a lidar reading. I've read about some tests that showed a very small benefit to the driver with their high beams on compared to their low beams. It was a SMALL benefit - hardly worth mentioning if you ask me.

Tony

 

I want to mention one thing about radar detectors.

If I pull someone over for speeding, I say they have fairly good chance at getting a warning - DEPENDING on the circumstances. In other words, if you're doing 10 over in a school zone, you're probably getting a ticket - versus doing 10 over on a city street - you'd most likely get a warning. These statements are generally broad and assume most things are equal when comparing one stop to another and so on and so forth.

However, if I pull someone over for speeding and they have a radar detector, they're almost guaranteed to get a ticket. I won't lower my "ticket threshold" and give someone a speeding ticket just becasue they HAVE a detector, but if they're bonafide speeding and my discretion is the deciding factor, then they're getting a ticket. And I can speak for most officers and say that this is pretty much an unwritten policy amongst us.

And if someone's getting pulled over for something else besides speeding and they hide the radar detector then that's one thing. But if they're getting pulled over for speeding and try and hide it before we get up to the car - believe me - we usually know when someone has a radar detector whenever we radar them, regardless if it gets hidden in time or not.

Just more info for everyone to enjoy reading.

Tony

 

That's why I dont bother hiding my detector. I know the officer that got me on radar/lidar knows I have it. Especially my ticket with lidar, I went from 75mph down to 45mph instantly when I got the signal (very far back). And there is no way to explain that without the radar/laser detector.

I HAVE gotten a warning with the detector once though, I was going roughly 15-20mph over on a 45mph road, but the officer made the mistake of turning his radar on too far back (was following me), so I was down to the limit before he was close enough to get a reading. He did pull me over, but he let me go, he knew what was going on then.

 

Sure there are several explanations
- You accelerated to pass someone outside of the officers view, and were slowing down (doesn't excuse exceeding the speed limit, but does explain why someone could go from 70 to 45)

- You saw the police car

- You saw the swarm of cars approaching the police car slam on their brakes. (I've noticed that even people that don't speed usually hit the brakes when they first see a cop)

 

Yes, genearlly that is true (for at least one polarization), unless you spend a lot of money on anti-reflective coatings. And even then.....

Yes... Headlights would introduce some amount of noise (they are approximately thermal blackbody radiators) and decrease the operational range of the lidar. The question is whether the difference is on the order of meters or millimeters! The calculation is fairly simple, but i'm in a rush right now. My guess is that it's very insignificant at the ranges involved and the speeds a car travels.

Intuitively I don't see how a longer integration time would help. I assume lidar is a pulsed radar system, in which case a longer integration time won't help you improve SNR. If I recall correctly, however, the power in a conventional pulsed radar echo signal goes something like R^4. The longer wait might just be a byproduct of having to give the car enough time to get within the reduced operational range of the lidar.

-Tom

 

1) I was pretty much by myself on the highway at night, no cars around me, single lane merging with 2 other lanes.

2) Police car was an unmarked Ford Explorer hiding behind the Bridge center support, you wouldnt even be able to see the guy during the day let alone when its pitch black out.

3) No other cars ahead of me to see him, they probably didnt even notice the car sitting there.

 

I guess I should have been more specific. There are many times where people may slow down - you gave some great examples that I totally agee with, by the way. Maybe what I should have said is that there are many times when it would be difficult or impossible to tell if someone had a radar detector. However, there are also times when I might say out loud, "This guy has a radar detector" before I even walk up to their car. I'm almost always right. This would be one of those topics that would take forever to explain and list examples to show my point, and if enough people are interested I might try, but I wanted to spend more time about radar opertation in general.

Here's something that although happens rarely, I always find interesting. Every once in a while I'll get someone on radar and after I pull them over they tell me I couldn't have because their radar detector never went off. Of course, my first question to them will be to ask if they had it turned on and/or plugged in and the usual answer is yes to both. So while I'm writing the ticket I can usually see the detector sitting on the windshield. I'll turn my radar on and off and off and on and it will just sit there and not make a peep. I'll then verify (with their permission) that it is a detector that can detect whatever band of radar I'm using (which it usually is). Every time this has happened, it's usually been a dirt-cheap model they purchased on sale at Wal Mart or the like. I've never had it happen with a higher-end model.

A friend of mine purchased one of these $39 radar detectors at Wal Mart one day because he didn't believe me. He parked next to me when I was working one day and every once in a while the thing wouldn't go off even if I pointed my radar gun right at it. Most other times it would take several seconds to go off. And a few times it would go off immediately. We also got similar results when I would park somewhere and he would do some drive-bys.

He also purchsed a radar jammer many years ago (too long ago for me to remember what brand) for a couple of hundred dollars. It never ever worked no matter how many times we tried it out.

Tony

 

Once again, I'm not a lidar instructor (only radar). But I've read many articles where they've tried all sorts of methods to defeat or delay lidar speed locks. Headlights and high beams were fairly insignificant but did actually delay the lidar's ability to get a speed reading. And when I say insignificant I mean that it's not even worth trying and certainly not worthy of giving anyone any sort of sense that it's doing any real-world good. I suppose at very long distances it might have more of an affect, but once the car is within normal lidar range it won't be a contending factor. Special license plate covers had similar results and if I remember correctly were SLIGHTLY more effective. Special sprays on the license plate and/or license plate cover had very little effect. Even with all three the difference is barely noticeable. And like you said, Tom, I guess if someone had the money they could get their car painted with some stealth paint - but I've never actually heard of this happening.

Tony

 

Actually, from what i've read thus far, defeating lidar seems like it should be trivial (no need for an AR coating paint job, which would be difficult if not impossible to do).

I haven't run the numbers yet, but a few well placed IR diodes (perhaps pulse modulated) should do the trick.

-Tom

 

I've got a Kustom Signals K-band radar gun I picked up just for fun. I normally just use it when some kids with a radar detector go speeding by, I turn it on and watch the brake lights. Although those with cheep radar detectors, such as cobras, never go off when I am behind them. I have to get in front of them before they go off and slow down. Kinda takes away from the fun.

I also want to agree with Tony, don't waste your money on any "radar jammers." They do not work.

Tony can you tell us the correct procedure the officer is supposed to go through while using radar. Visally estimating the speed and THEN confirming it using radar and such. Some officers have told me they dont estimate speed and one officer even told me, "All I do is aim it at the cars and it tells me the speed." I was like your kidding me right. I'm only 16 and know more about the use of radar then you do. I didn't say that of course.

 

Also Tony, I have a question about jurisdiction lines and the use of radar.

1.There are a few major speed traps around here. They are in small little 3/4 mile long munisapalites with one major road going through it. They are there 24/7 and write tickets for 1MPH over all of the time. They sit right on their city's line and radar vehicles not yet in their city. They then make traffic stops on those cars and give them tickets for speeding. Can they do this?

2. Can an officer chase after a car out of his city without his lights on then make the traffic stop out of his jurisdicion?

3. Can a state officer follow, stop, and write a ticket to a car he has followed into another state with his emergency lights on?

 

I think that depends on the area. I know in Michigan, a police officer can cross county lines if he's involved in a chase, but if he is not chasing someone he has to call and get permission to cross into another county. (one of my friends found that out the hard way)

 

Thats what I thought, cops in these small towns around here are always crossing out of there area to make traffic stops, most of the time they have there lights on. There have been quite a few times though I have seen the cops cross the line and then later turning on their lights. I know they haven't called it in because I have been listening to my scanner. They only call it in after the stop.

Also another question what about a cop that is out of his city and sees you speeding/ driving reckless. Can he stop you even though the crime didnt happen in his city?

 

Hey everyone. Just had a death in the family. I will get to your questions as soon as I can.

Tony

 

Im sorry to hear about that. but while youre gone im jus going to post a question to be answered by whoever and whenever.

1) Range - When i was in school they would always have these "demonstrations" by our local police at our shcool and for fun they would pick out somebody and have them run across the field to get a speed reading or something. if i was listening correctly (which i never was) i think i heard one of the officers say that the range of a radar gun getting a reading on a car going about 65 would be close to the size of a football field (apprx. 360ft - 400ft) is this true or do i need to brake sooner.