Michael Boatwright, Dedrick Williams, and Trayvon Newsome are facing first-degree murder and armed robbery charges for gunning XXX down in front of a South Florida motorcycle shop more than four and a half years ago.

On the first day of the trial this week, a defense attorney claimed that Drake -- who had been beefing with XXX when he died -- may have been involved in the killing.

"[XXXTenatcion] is killed by two men, right?  He came on social and says, before he dies, 'Guys, if anyone kills me it's Drake.'Do you think in that time frame anyone addressed [Drake] or talked to him?  No.  Do you think sitting today years later any detective has asked Drake?  No, they never did that.  The reason they wanted security for [XXX] on the day that he was shot was because he had problems with Drake and Migos," the lawyer argued.

Robert Allen pushed back on that yesterday.

Allen was initially charged with Boatwright, Williams, and Newsome for the killing.  However, he took a plea deal and is testifying against the other three.

He told the court that nobody hired them to kill XXX and that they did it because they wanted to rob him.