Killers can change their lives. The Birdman of Alcatraz was a killer and he changed his life. Hell, even the Son of Sam turned his life around belief-wise.
They can and many do - but it’s really hard to “change” your life if you will not admit your culpability to the crime you’re allegedly remorseful for.
Any 12 step program starts with admitting you have a problem. Any change in your life begins admitting you screwed up.
OJ could have done this and never faced a consequence legally - he “won” his freedom at a criminal trial - he lost the civil trial and paid the damages (certain assets/income was protected).
The man was a PROVEN violent criminal - busting into that hotel room with guns showed that. He would have very easily admitted- yea - I did it and shown remorse. Instead - he tried to profit by writing a book saying - I didn’t - but if I was going to do it - this is how I would have done it.
Prior to those murders - he was the athlete everyone loved and trusted. He was on par with Magic Johnson on a like ability scale - he was black - but whites trusted him, he was personable and looked good on TV.