Boston University on Thursday released the results of its investigation into Aaron Hernandez’s brain, in which they found a severe level of CTE, the brain disease that’s linked to concussions and is believed to lead to violent behavior and suicide.

Hernandez killed himself in April while serving a life sentence for murder.

That Hernandez had CTE isn’t surprising, but that he had such a serious case of it is, because his football career was relatively short. The Boston University findings suggest it doesn’t take much for a football player to get CTE – a few years of full contact is enough to do the trick.

Dr. Bennet Omalu, the doctor who discovered CTE and on whose work the movie “Concussion” staring Will Smith was based, told TMZ that there’s not a doubt in his mind that the disease drove Hernandez to violent criminal behavior and suicide.

Also, Yahoo Sports’ excellent Dan Wetzel wrote under the headline, “That Aaron Hernandez had CTE is devastating news for the NFL,” and followed that piece up with a report Friday that said Hernandez’s case is the hot topic being discussed in NFL locker rooms right now.

The lawyer representing Hernandez’s family is suing the NFL and the Patriots, claiming the league and team did not do enough to protect is players from concussions.

The NFL responded to that lawsuit on Friday, saying it will fight it vigorously. The league also stressed that Hernandez is not the victim here – the person he killed (or people? He’s only been convicted of one murder) and his family are.

This time, we agree with the NFL, and that’s a rare occurrence. No, we don’t mean to pooh-pooh the seriousness of CTE, but we live in a society of excuses, and the notion that a few hits to head made someone murderer appalls us.

If you murder someone, that’s on you.