I think he wanted to go to prison. My theory is that he didn’t get the clout/infamy that he wanted from the murder, which is why he confessed and does not have an attorney.
He confessed because he got a plea deal and immunity from prosecution. The problem was the immunity only covered one jurisdiction, and he was liable in more than one jurisdiction
Guess he wanted to leave a legacy, and being known as the guy who killed Tupac was better than anything that he created himself. It’s sad that this was the best he could do.