Any lawyers in the house who could comment on their refusal to test his hands?
Can they refuse to run a test because they're afraid it might produce exculpatory evidence?
Can they refuse to run a test because they're afraid it might produce exculpatory evidence?
> A number of techniques designed to detect gunshot residues (GSR) on the hands of a suspect or victim have been developed. These techniques range from the now-discredited paraffin test to the more modern techniques which use instrumental analysis or scanning electron microscopy. The limitations of all GSR techniques are that the residues can be removed by rubbing or washing the hands and usually must be collected soon after the firearm is fired, yet even valid GSR tests are not conclusive.
https://www.ojp.gov/ncjrs/virtual-library/abstracts/forensic...
Never talking to or cooperating with police, unless legally required as advised by your lawyer, is what's known in legal circles as "smart."
If LEOs and prosecutors are incentivized based on raw arrest or conviction counts, then the consequence for being wrong should be astronomical (say, the sentence of the wrongfully convicted times a ≥ 1x multiplier).
The idea of incorrectly convicting someone for a serious crime not only is an injustice to the innocent, it leaves the community in an unsafe and unwitting position regarding an actual perpetrator. In those cases it would be better to have no law enforcement involvement at all.
If they truly believe you are guilty then convicting a larger portion of guilty people even via impure means is a net good for society and incidentally for their career.
In my experience, it's mostly that they are lazy, incompetent, and/or have their mind made up. In some cases, it has to do with costs (eg they aren't going to DNA test a petty theft crime scene).
Contrary to TV, forensics are actually used very rarely in the criminal justice system. Most of the ones that are used are fingerprints and drug tests.