Actually, Martin said the fourteen women's rings and sets of earrings, and the woman's watch, belonged to a friend. However, he refused to identify that friend.
That stash was found when Martin and some friends were caught on surveillance cameras putting graffiti on lockers. When school security caught him, they went through his backpack thinking they would find whatever was used to put the graffiti on the lockers (none of the stories i read said if they were looking for spray paint, a paint marker, a Sharpie, or something else).
That's when they found the flat-head screwdriver, which school officials called a 'burglary tool", and all of the women's jewelry.
I’ve wondered if the jewelry was bartered for marijuana and Martin was going to give it to his dealer.