Forensics Enthusiasts, I have a question...

[YellowRubberDuckie]

I was just watching something on A&E about The Green Beret Murders. OK, answer me this: Why, when there is a lack of finger prints on a weapon, do they get suspicious? I mean, EVERYONE who has EVER watched a crime show knows that if you don't want to get caught the first thing you do when you commit a crime is YOU WEAR GLOVES so you don't get fingerprints on your weapon. I don't know if this guy really did what they convicted him of or not, but why isn't there common sense in investigation? I mean, SO MUCH can be explained away simply, and if you can do that, they're like, "Oh, that's too simple." But don't you think that usually, the simplest explanation is actually the answer. Am I wrong here?
Duckie

[TNDemo]

1. I am not sure if I saw this one or not

but have watched shows about those murders before. I think I tend to think he did it. What do you think?

I want your dog.

[YellowRubberDuckie]

5. I get the impression that he DID do it...

But I still can't figure out the motive.
Duckie

[TexasSissy]

2. Well, dope fiend druggies on a murderous rampage rarely wear

surgical gloves or stay at the scene to clean up evidence. That was the story McDonald gave....the killers were whacked out hippies who did the murders in the Charles Manson style (the Manson murders had recently happened; and in fact, there was a magazine on McDonald's turned over coffee table that had the Manson murders as the cover story.....with a bloody fingerprint on the magazine). The fingerprintless gun would have, therefore, been consistent with someone wearing surgical gloves (McDonald was a surgeon) or someone wiping the gun of prints.

Have you not seen the made for TV movie or read the book about this incident and the ensuing trials and hearings? They were called "Fatal Vision." Both the book and the movie were great. Spellbinding, in fact. It goes through the evidence in some detail.

[YellowRubberDuckie]

4. Did I say surgical gloves? No.

Leather gloves would have served the same purpose.
Duckie

[TexasSissy]

6. Okay...dope friend druggies rarely wear LEATHER GLOVES to go

on a murderous ramage.

Okay?

[YellowRubberDuckie]

7. Maybe if it's cold outside?

I get what you're saying, and I agree. But it's not something you can completely dismiss as a possibility.
Duckie

[TexasSissy]

9. I can see you haven't spent much time around drug addicts or violent

people. Not that I have....the latter, anyway.

But no, it's not feasible or within the realm of real possibility that the "group" of hippies who supposedly performed the deeds (extremely violent, brutal, haphazard, overkill) AND fought with the husband/father McDonald, were wearing gloves.

It's possible to the extent that anything is possible, but feasible? No. The murderers of Sharon Tate and the others at that house did not wear gloves or protective clothing, or seek in any way to hide their identities, clean up evidence, or even hide themselves. The murderers of the LaBiancas did not do that, either.

But this is a red herring, anyway. McDonald wasn't convicted because there were no fingerprints on any of the weapons.

[TexasSissy]

8. Correction - should've said knife or icepick (not gun).

[luaneryder]

3. Jeffrey McDonald?

I think I see what you're asking and I would agree that sometimes the simple answers are dismissed as being too simple. I was stationed at Bragg with 1st SOCOM some years after the event and even then the quarters were still under police control and the murders were still one of the main topics of conversation. A lot of folks were still on active duty that served with the captain and the prevailing thought was that he was guilty. I wish I could have seen that program.

[jukes]

10. let me wade in a bit

i was "punished" once by being sent to latent fingerprint development & fingerprint ID classes.

caveat: not familiar w/ this case, so generalizing only.

guns aren't the best vehicle for latent prints. prints are primarily composed of body moisture; mostly water, w/ assorted salts, fats & minerals in solution. when a print is discovered by dusting, it is usu because the water content has been absorbed or evaporated, leaving behind a sticky residue of mineral & fats. the dusting medium readily adheres to these deposits, excess it brushed or blown off, & you get a darkened print.

on a hard, slick surface like a firearm, the moisture does not absorb and metal is generally cooler than ambient temperature, so moisture is retained. a wet print smears when dusted.

add the oily protective coating on weapons, there's little chance a coherent print will remain.

other variables: when a person is fingerprinted for identification, great care must be taken to gently roll the finger across the surface w/o allowing it to slide. most latent impressions are partials, that is, only a section of the finger ridges leave clear marks because when we handle an object, we don't concern ourselves w/ avoiding any sliding motion. in fact, w/ firearms, there is almost always an "adjustment" made between carry grip and aim/fire grip. recoil shifts the weapon, smearing contact.

it's actually very rare to find a usable latent on a weapon. if memory serves. @ least 7 of a possible 21 identifying features must be clear in order to make a valid comparison. it just doesn't happen often. statements that "no prints were found on the weapon" are inflammatory & misleading, a cheap lawyer trick. it usu means no USABLE prints were found.

also, a quick wipe w/ a shirttail will clean any weapon of latents in half a tick, and any criminal knows this. it's taught in our prison-system crime schools, one con to another, if the mope is too stupid to pick it up from TV.

a lack of evidence is just that. it isn't evidence.

mon deux piastres.

[YellowRubberDuckie]

11. Murders were committed with an ice pick and a pairing knife.

[jukes]

12. well

my post was useless then, wasn't it? after so carefully trying to focus on the keys due to the multiple substances coursing through my system.

wooden handles are good surfaces for latents. i'll go away now. bubye! sorry!

[YellowRubberDuckie]

13. Don't talk like that. That was good info...