#1 - when the cops approach you and ask Qs, you immediately do one thing - ask for an attorney.
Dude tried to talk his way out of it. badddd idea!
Lawyer up. Let the attorney issue a statement saying "the robbers stole the car without permission, my client had no knowledge of this".
At that point, it's the word of this guy against 3 murderers. He doesn't get charged with anything.
"Sure, you can have an attorney, here is the number for the public defender"
and guess who the public defender's office works for?
Rob, one of the many reasons why many people are criminals, is because they think are slicker/smarter than normal folks or the police. Doing the smart thig like you said, doesn't go thru the average criminal mind..."sure, I'll talk", but due to feeling guilty, and a sense of ego, they usually eff it up for themselves.