I met and spent a lot of time with a man I consider a borderline sociopath in Australia.
He fit in well with society. I don't think he would have blinked if he thought a murder would benefit him some how, if he believed he could get away with it.
He is now deceased. Cancer got him.
In some jurisdicitons, 70% or more of murders are never solved. New Orleans cleared 28% of its homicide cases in 2016. Detroit cleared 15%.
They will you in a minute if you stand between them and something they desire, but usually only if they think they can get away with it. So in this case a psychopath would have followed the victim unnoticed to home or to work and planned out an opportune moment to kill him.
The low clearance rates you cite are not a sign of a higher level of psychopaths or sociopaths, but of fear of gang retaliation and the fact that many blacks prefer high crime from other blacks rather than cooperating with white police to put criminals in jail.
New Orleans and Chicago have many Obama sons spiking the numbers of violent activities, and suppressing the number of thorough investigations to solve crimes in areas that get you fired for aggrieving the violent collective.