It was in the early hours of the morning on Thursday when police say 27-year-old Michael Adams entered a Circle K convenience store in Peoria, Arizona. Inside was 17-year-old Elijah Al-Amin, who, his parents say, had just gotten off a late shift at Subway, one of his two summer jobs. Adams, who had been released from prison two days earlier, allegedly approached Al-Amin from behind while the black teenager—a rising senior in high school—stood at the soda machine. Adams then took a penknife out of his pocket, stabbed Al-Amin in the back, and slit his throat, according to a police affidavit. Al-Amin staggered out of the store and collapsed near gas pumps as witnesses unsuccessfully tried to save him. When Adams was apprehended by police shortly after, he said that Al-Amin had neither said nor done anything to threaten or provoke him. Adams explained he had attacked Al-Amin because he had heard him playing rap music in his car in the Circle K parking lot before going into the store, which made him feel “unsafe.”

Adams walked away from the crime scene with the knife in his pocket and blood on his hands, arms, and feet when he was arrested without incident. Adams explained to the officers that “rap music makes him feel unsafe, because in the past he has been attacked by people (Blacks, Hispanics, and Native American) who listen to rap music,” the police report said. “Adams further stated, people who listen to rap music are a threat to him and the community.” Adams said he carried out the chilling murder because he felt he needed to be “proactive rather than reactive” in an effort to “protect himself and the community from the victim,” according to court documents.

“My son didn’t drink, smoke, do drugs, party. He loved music and working. He was focused on his goals,” Al-Amin’s mother told CNN. “He started mowing lawns at 13 and saving money because he wanted to own his own business very young. … He recruited other kids to work for him in the lawn business, and he was so good. I was so proud of him.

“He’s a good boy. He’s a good baby. He’s my baby, and I have to bury him,” she said. “I’m on my way to bury him right now.”