Palmetto Bay, Fla. ? A 14-year-old boy was charged with murder in the slaying of a classmate, a musician and baseball player who was found bleeding to death in a middle school bathroom.

A fellow student said the victim and the boy accused of killing him were friends who competed with each other to get top grades.

Jaime Rodrigo Gough, 14, was found early Tuesday at Southwood Middle School, a magnet school specializing in visual and performing arts, authorities said. His neck had been slashed.

Michael Hernandez, 14, signed a statement admitting he killed the boy and the knife used in the attack was found in his backpack, Miami-Dade County police Detective Randy Rossman said Wednesday. Police had obtained a search warrant for the backpack.

Hernandez was charged with first-degree murder late Tuesday and waived his right to appear Wednesday in juvenile court. He was placed in secure detention.

Police said Gough and Hernandez knew each other, but refused to discuss a possible motive Wednesday.

Megan Hopper, 12, shared the same first-period class with Hernandez. She said he was late for class Tuesday and arrived with blood stains on the collar of his white T-shirt, pants leg and shoes.

He offered a variety of excuses, telling their teacher he bumped into someone, and his classmates that he bumped into a door or had a nosebleed, she said. Hernandez was removed from class around lunchtime.

Hopper recalled Hernandez downloading gruesome pictures of decapitated heads from the Internet but otherwise described him as fun and talkative.

“The only thing he’d usually do bad was chew gum in class,” she said.