Although the rape victim states she had a pack of strawberry gum during the attack, the pack of chewing gum Brenda reveals on the table is labeled 'Stawberry Sugar Free Gum.'
When first analyzing the crime scene, it is found that the victim, Manuel, has puked before dying, and Brenda finds a strawberry chewing gum in the puddle of puke on the floor. Yet later when Brenda interviews the girl who shot Manuel, the girl says that when he put down his gun to unwrap a stick of strawberry gum she offered him from her bag, she grabbed the gun and shot him. So Manuel has not had a chance to ever eat/swallow the gum.