Question for muzzle flash experts

[p35]

This is a question asked by a fellow attorney:

"This concerns the visual "proof" of a gun being fired. In my hypothetical case, the police have a surveillance video of a car being driven on a street. They allege the person driving the car reached from the driver's front seat, across the passenger, and shot out the window at a person on the sidewalk. This allegedly occurred at 7:15 p.m. in late September last year. Other cars on the video have their headlights on.
Neither the car nor who is driving it can been seen clearly enough to ID a license plate, type of car, etc. - but I am just checking to try to go one step further.
If, given evening lighting conditions and a dark picture, I am trying to find out if there should be some kind of flash if, in fact, a gun was fired from that car."

This was apparently a .40 cal S&W. Don't know what the ammunition was.

Anyone have ideas?

 

[ribbonstone]

Depends.

We've all seen video of real life shootings, and many times there is no flash to be seen,,sometimes there is. Certinly the absence of a flash would not be proof positive that a shot wasn't fired.

 

[MNgoldenbear]

Not surprising that there may be no flash visible with a surveillance video.

1) You don't specify date, but using 21 Sept and Seattle as a sample, USNO calculator (http://aa.usno.navy.mil/data/docs/RS_OneDay.html) gives "sunset" as 7:09 and civil twilight (often end of shooting time for hunting) as 7:39. It ws probably relatively light out, regardless of vehicles having headlights on.

2) Depending on the video, I've seen some where there's quite a bit of gap between "frames", enough to miss the flash from a shot.

I would say that a pistol will normally PRODUCE muzzle flash, but whether it is VISIBLE or RECORDABLE with available equipment is highly variable.

 

[P95Carry]

Muzzle flash at a distance is often muted and some powders give quite a dull orange. Add this to the perhaps limited spectral sensitivity of some vid cameras and maybe hard to see much.

A CorBon out of a snub might well light things up a bit but - OTOH a GD out of a semi might be real dull.


Unlikely you'll see this much (sorry - I often post one of my fave pic successes!) - any excuse!

 

[EddieCoyle]

It also depends on the frame rate of the video. Typical surveillance video has a low frame rate. The flash could've come and gone between frames.

Once, a friend used her phone to take a video of me firing a .30 Carbine Blackhawk. That gun is an absolute flame thrower. Of the 6 shots on video, three showed little or no muzzle flash - even though in reality it looked as if the gates of Hell opened when I fired it. The reason? Crappy frame rate.

 

[P95Carry]

Excellent point Eddie and not sure why I forgot that!!

Indeed slow frame rate leaves huge chunks of time for not recording such short events.

 

[Steve C]

I have a movie of a friend shooting a .357 mag. I'd shot it with my digital camera at a frame rate of 28 frames / second. Of the 6 rounds the muzzle flash was seen in 4 or the rounds that went down range and 2 of the shots no flash was recorded. This indicates the flash duration is much less than 1/28th of a second as the shutter is open for a shorter duration.

 

[unspellable]

electronic flash

Typical electronic flash lasts on the order of 0.0001 second or 0.1 millisecond.

There are special purpose flashes that are faster but they are expensive and not the sort you expect to see in the display case at the corner camera store.

 

[MachIVshooter]

During daylight, most conventional handguns will produce (at most) only a very small plume of smoke that dissipates so quickly you may not see it if you blink. Even flame throwers like the .50 AE or .454 Casull using powders like H-110 (well known for fireballs-trust me) do not show much in broad daylight. couple this with the low resolution and slow speed of most surveillance cameras (and then factor in distance from focal point) and you probably wouldn't see anything. However, if the pistol is visible you should be able to catch either the action cycling, the gun recoiling or the empty case in the air somewhere between gun and ground.

At night, however, the aformentioned big magnums are quite a spectacle.

 

[Mal H]

p35 - Let's ignore the flash question for a second. Can you see anything resembling a gun in the video you describe as being so poor you can't even ID the driver or even the type of car it is? If you can see a gun or just a hand holding an object reaching across towards the passenger side window, then the video should be able to detect the recoil of the object. A .40 held at arms length is going to display recoil, more or less depending on how strong the unidentified driver is. Maybe that will help determine if a shot was fired. It's very hard to disguise or imitate genuine recoil.

Now, if you can't ID the driver or the car and you can't see whether a gun is even in the driver's hand, why pursue that angle at all? Of what use would it be in court? Purely for curiosity's sake?

 

[p35]

Mal-

I haven't seen the video- like I said, I asked for a colleague who isn't into guns. I think she's basically looking for any angle that would help prove that her client didn't do it. If a bright muzzle flash would be expected to show on a video where details can't be seen, the absence of one might help show that her client didn't fire the shot as alleged.

As far as what use the tape is in court, you're right that it's not great evidence against anyone in particular. OTOH, it might help back up the alleged victim's story that "I was on the corner of X and Y at 7:15 on September 23 and someone drove by and popped one off at me." Like they say in law school, a brick doesn't have to make a wall.

A year or so ago I had a burglary case where we had video of the perps breaking into the store, but the quality was so bad that you couldn't identify them. Neither side bothered to introduce the tape at trial, because it didn't help prove anything. That could end up being the situation here, but as I said at this stage she's just checking out any angle that might help her case.

 

[Michael Courtney]

I am a forensic scientist who specializes in ballistics. My PhD is in Physics and I am the director of the Forensic Science program at a state university. The attorney should contact me at [email protected].

With details about the gun, ammunition, camera, and other incident details a reconstruction can easily determine whether or not a muzzle flash would be seen on camera. In addition, if an audio recording is available along with the video, that should be much more conclusive as to whether or not a gun was fired (there is no gap in an audio recording).

I have a goal of doing a couple of pro bono defense cases each year, and this could be one of them if it looks like someone has been falsely accused of a gun related crime.

Thanks,

Michael Courtney

 

[p35]

FYI- response from the attorney with the question:

Mike,
I can't thank you and the knowledgeable gun-enthusiasts who responded to my question enough. The information is really helpful.
"Thank you" just doesn't say enough!
I hope I can return the favor some day.