Police have discovered major evidence in XXXTentacion's murder case in a Cadillac owned by the grandmother of Michael Boatwright, who was the second of four suspects arrested in the shooting.

According to TMZ, investigators found two dark-colored masks, which fit the description of the masks allegedly bought by Dedrick Williams before XXX was killed. Williams was the first of the suspects to be arrested.

Besides the masks, cops found .22 caliber bullets, which match the kind of ammo that was at the murder scene. There was an AR-15 style assault weapon in the trunk. Police also searched Boatwright's cell phone and saw that after XXX was killed he searched the rapper's name, as well as the term "accessory to murder." (Doh!)

Earlier this week, police arrested Trayvon Newsome, the fourth and final suspect in the case. Newsome was taken into custody in Broward County, Fla. after he turned himself in through his lawyer. He's been charged with murder in the first degree and robbery with a deadly weapon.