Prison studies have documented that criminals are generally of sub-par IQ. Where 100-105 or so is normal, most criminals are in the low 90s.

But some criminals are outstandingly bright – yet not bright enough to draw the proper conclusion: getting away w/ murder is virtually impossible. It is less impossible when a criminal murders another criminal because for such crimes there are liable to be a plethora of suspects. But for murders of law abiding people there is often just one obvious suspect who had a motive or benefitted from the crime.

Nor is that the perp’s only disadvantage. Another big one is that there are usually several detectives assigned to solve such a crime. The criminal may be much smarter than any of them individually if, for instance, he has 150 IQ. But one150 IQ vs. 3 100 IQ cops (=300 IQ) is no contest.

Next, the detectives have the insuperable advantage of a wealth of experience to look back on while this is probably the perp’s first murder. An allied point is that the cops have the advantage of hindsight whereas the perp has only forethought – and nothing goes exactly as he planned it.

A habit I have developed is watching true crime shows, e.g., Forensic Files. And the one thing that these shows prove is how difficult it is to get away w/ murder.

A point sometimes raised by critics is that if only murderers watched such shows they would learn how to commit their crimes and not leave evidence. Well, I have now watched a couple of shows w/ high intelligence Forensic Files-watching murderers – and it didn’t help.

Let me relate one of those cases. A very intelligent teenager murdered his father, taking numerous precautions to eliminate evidence and mislead police. But he had unsuccessfully solicited numerous friends to kill his father. And he had "rented" the gun from another friend. 

Prosecutors don’t need forensic evidence when they have half a dozen witnesses.

But they had plenty of forensic evidence anyway, and inferences where they did not. For instance, ballistics revealed that four different brands of .22 ammo were used. Obvious inference: four different killers. BUT it was snowing outside and only one set of tracks went to the house: Obvious inference: one killer trying to create a misimpression.

And trying to create a misimpression itself spotlights the perp. The misimpression sought to be created was that the killing was a burglary-gone-wrong. BUT all but one of the cartridge casings had been picked up and disposed of. How likely is it that panicked burglars picked up and disposed of their shell casings?

The bottom line here applies to virtually all murders: strangers don’t clean up crime scenes or try to create misimpressions. Strangers don’t need to do such things. They just leave – because they have no connection to the crime scene. People who take the trouble to clean up crime scenes do so because they have some connection they cannot deny to the crime scene. Like being the victim’s son who lived w/ his father in the house.

The kid "cleverly" scratched up the inside of his friend’s gun and gave it back to him. The scratches killed the ballistics but produced an obvious inference --why would anyone scratch up the inside of their rifle unless they were trying to get away w/ having misused it?

The killer had borrowed his friend’s shoes and worn them when he walked to the house to do the killing. But then he was fool enough to give them back to his friend rather than throw them away and buy his friend a new pair. Not that that mattered anyway. Because how would he explain buying his friend new shoes?

One of the greatest difficulties of murder is that the perp has to do it himself entirely alone – which makes it difficult to explain where you were when the killing was done – or hire someone else for help. The latter choice is especially problematic when the friends are other teenagers. You just cannot rely on them to be close-mouthed. No matter how contrary it may be to their interests, the others talk – especially do teenagers talk. In this case the friends bragged to girls whom they were trying to impress and the information was promptly relayed to the police.

This epitomizes the problem of using others. If they are really bright what you have done is subject yourself to life-long blackmail. And what if the other is a lover or spouse? Well, buddy, you better be sure and stay with that lover or spouse for life because you sure can’t afford a nasty breakup. Innumerable cases have been solved w/ the aid of information from an embittered ex-lover.

Neither can you afford to hire someone on the cheap to help w/ a murder. Innumerable cases have been solved because a nitwit accomplice paid $500.00 for his help promptly took it to a bar and bought drinks for the house and shot his mouth off.

I believe it may have been Machiavelli (sp?) Who said the only way of keeping a secret two others know is to kill them too. And for each new murder you duplicate anew all the problems set out above for yourself.