I saw a very similar phenomenon with a good friend of mine who killed someone in a drunk driving accident. The reactions of his close friends and family members were strongly split between acceptance and denial, it seemed. The acceptance group, which included myself, definitely had a more difficult time processing everything. There was just no getting around the fact that he had done a terrible, terrible thing that didn't just earn the hatred of the victim's family, but of society in general. You know that there really isn't much defense you can offer, and it is was very difficult to reconcile his actions with who you believed him to be as a person. Eventually, the acceptance group all seemed to just say to themselves "He did a terrible thing, but I also know him as a good person." It's all there really was to do.

The denial people, which included his brothers and many of his friends, had a much easier time of it. They seized onto ridiculous rumors, the most common one being that he took the rap for a different person who they claimed was actually the one driving(there was absolutely no evidence of this whatsoever). They, like your friend, blamed the police for mishandling the situation. They claimed that, while my friend may have been drunk, it was actually the victim who caused the accident(again, no evidence whatsoever; my friend indisputably ran a red light). To this day, over fifteen years later, I am still angry at the denial group.

I took two lessons on human nature from this. My friend was a very popular guy with a lot of friends, and the very interesting thing to note is that not one person he knew turned on him. Not one person he knew, from close friends and family to acquaintances, said "fuck this guy" and washed their hands of him. Everyone defended him. The only difference was in the manner in which they did so, acceptance or denial. The lesson here is that people are inherently prone to forgiving the ones they love. I try to remember this when I see people on the news who have committed terrible crimes. I remember sitting in front of the TV watching my friend be led out of the courthouse in handcuffs and said through tears to nobody but myself "He's honestly not a bad guy."

The other lesson was that otherwise normal, reasonably intelligent people will often resist accepting a harsh truth to a very alarming degree. They will believe ridiculous things they would ordinarily never believe, and they will find holes in a theory even when there are clearly none to be found. Given the choice between accepting the difficult reality or constructing a false one, many of us will choose the latter. It is certainly easier.