Removing Gunpowder Residue From Clothes, Skin

Recent developments in the Robert Blake crime case seem to partially center on the fact that his clothing from the night of his ex-girlfriend’s murder was allegedly covered with gunpowder residue.

Just how hard is it to remove this residue? Couldn’t Blake have just tossed his clothes into the washing machine, or is more a thorough cleaning needed, especially given the exceptionally sophisticated detection technologies that police departments use today?

Also, I recall a television crime program about five years ago in which the detective, sympathetic to the killer’s cause, leaves him in the precinct washroom with a can of Comet, advising him to “scrub hard,” so as to remove the gunpowder residue. Again, how difficult is it to thoroughly remove said residue given existing technologies? How practical was this advice?

General rule:

don’t rely on TV shows for crime-planning :rolleyes:

Well, I haven’t found a good answer to the question in the OP, but after a little googling I did run across this:

Geeze, there’s a website for everything these days…

do you know what a ‘picogram’ is?

it only takes 1-2 of the things to be detected.

scrub well

Why not, if one is planning a crime in advance, simply purchase two copies of each article of clothing?

Dress, go to your target’s location, fire your weapon. Get to a secure location, dispose of those clothes, shower, and don the EXACT same outfit you had before, only a brand new one.

Also, you’d think someone would try to wear a coat while firing the gun, or stand behind some sort of shield such as a door or something.

I think that washing makes a postitive detection much harder, but it’s still technically possible. I’m not sure how well some ‘single fragment of gunpowder’ would hold up in court versus a conclusive amount. Probably he just didn’t really think about getting rid of all of the evidence.

The big thing to remember is that most criminals are not executing some long-architected master plan. They are committing their crime on the spur of the moment and generally figure they won’t get caught, so they don’t wash everything, completely get rid of the gun, and take other precautions that would make it harder for the police to track them down. A lot of criminals turn to crime because they’re too dumb to make it legitimately; there was a case a while back where a guy had the police stumped. They had a very strange gunshot wound, with no rifling marks on the bullet and some weird ballistics, and they weren’t sure what the weapon was. However, when they found a revolver with the barrel removed sitting in the house of their initial suspect during a search, they were easily able to pin the crime to him.

That’s why serial killers are so much harder to catch than an ordinary murderer. An ordinary murderer will kill his victim on the spur of the moment based on some sensible connection (‘he owes me money’ ‘he’s made fun of me for the last time’). Meanwhile, a serial killer generally obsesses over what he’s going to do for a long time beforehand (and so does a good job destroying physical evidence) and picks his victims on some apparently nonsensical basis (they have a reason, just not one that would sound sensible to an ordinary person).


Another reason it’s hard to catch serial killers is that there’s no motive. If your girlfriend or boyfriend is murdered tomorrow, the first person they’re going to question is you. However, if just some random dude gets killed someplace, you won’t be questioned unless something ties you to the crime.

From everything I’ve gleaned from all the news accounts of various crimes, it appears that the best way to get away with it is to never become a suspect.

All Blake has to do with small amounts of residue is say that he touched the body and the residue wiped off on him, which is probably true. Braun is a clever lawyer, and he will have already thought of this. Now if Blake has the full pattern of residue, he’s got free room and board for life.

If Blake was really clever, he would have gone to a shooting range earlier in the day, and shot off a bunch of rounds in public. That would explain and gunpowder residue.

But he’s never struck me as “Sherlockish”. In fact, as far as I remember from his series, he seemed to solve most crimes by talking to his parrot.

As DPWhite alludes, the real issue is how much residue is needed to convince a jury beyond a shadow of a doubt. If you possess specific expertise in this area, I would certainly be interested in whether 1-2 picograms of residue is usually sufficiently compelling evidence–or whether courts usually impose a more stringent standard.

Moreover, is it possible to forensically “date” said residue? If Blake had immediately laundered his clothes after the alleged incident, couldn’t he later claim that the post-laundering residue (if any) had been there from an earlier practice shooting?

A prime case of:
stating the obvious

:stuck_out_tongue: [sup]I’ll keep this in mind[/sup][/ul]

Every time I shoot someone, I lather up pretty good with hydrogen peroxide afterwards.

I seem to remember reading somewhere (stop me if I get too technical here) that mobsters used to bathe in vinegar after a crime to remove the residue. Not sure if that still works in light of modern technology.

I seem to remember reading somewhere (stop me if I get too technical here) that mobsters used to bathe in vinegar after a crime to remove the residue. Not sure if that still works in light of modern technology.


I read something along the same line, but it refered to a XIX° century riot, when the “forensic” method used would be to smell one’s hands and clothes. I’m not convinced it would be very useful nowadays.

In short soap a water is enough, I assume washing for as long as a kitchen worker is required. I got the info. From the DOJ site. More info the police needs to test a suspect ASAP. Within 4hour of gun fire for a solid result. The sample weaken with time and they won’t even test a suspect if it looks like a suspect had wash

Whew! Only took 19 yrs. I hope Robert Blake made it through his ordeal ok…

Around 2003 I found myself in a training facility, teaching a class. In that same building, explosives were being detonated several times a day to train people in bomb disposal.

Upon conclusion of the training I was running I found myself at L.A.X. My tool kit- which I always carried on- was swabbed and I was removed from the line by a very angry and tense supervisor. Apparently everyone in that class touched doorknobs and other surfaces in the building and basically there was explosive particulate all over the place.

I touched same surfaces, got it on my hands and clothing- and handle of tool kit. I explained where I had been. Fortunately, my client had given me his card as I wrapped up and I produced it. By that time I was in danger of missing my flight, but I was pretty sanguine about it. It didn’t matter when I flew, just that I was not placed onto some No Fly List.

A call to that person confirmed where I had been and what I had been exposed to. I was allowed on the plane.

Point of the tale is that with just minute traces of explosive material I was assumed to be someone who had prepared explosives or used them in the recent past and was therefore a threat.

An acquaintance has a job conducting research on/with high explosives. When he flies, he carries a letter from his employer explaining to TSA agents why he tests positive for explosives residue.

THAT woulda been useful !

I was visiting a mining community once, and asked the airport security about how many people test positive for explosives, considering a large number of the miners would actually work with the stuff and residue actually gets around. He said that yes, they get a few positives a month. My follow up question after this thread would be - doesn’t handing spent shells or going to a firing range also give a positive swab result at the airport?