HOUSTON -- An argument over a T-shirt may have sparked a teenager to fatally stab his older brother, KPRC Local 2 reported.

Houston police said a 15-year-old boy killed his 17-year-old brother, Robert Dewayne Benton, at the Parker Square Apartments on Shady Lane near Parker Road at about 3 p.m. Wednesday.

"They got into an argument about something frivolous," Sgt. Phillip Munoz said. "It escalated and ended up (with) one grabbing the knife and stabbing the other one."

Benton was taken to Lyndon B. Johnson Hospital, where he died.

Investigators said the younger brother confessed to stabbing Benton in the stomach because Benton was wearing his T-shirt.

"They fight a lot but it ain't never got this big," neighbor Gladys O'Brian said.

The teenagers' mother and several other children were inside the apartment at the time of the killing, detectives said.

"From the hallway, they started fighting and then they took it to their room," friend Shay Govin said. "I walked back into the kitchen and he was just holding his stomach. There was blood all over the place."

"I said, 'Robert, you all right? He kneeled down and he laid back and he was just gushing," friend Terry Govin said.

Police said they referred the case to juvenile authorities on a murder charge.

Investigators said he might have a mental illness.

"I don't think the baby should be charged. I don't think he should. He didn't know. He didn't expect to hurt his brother," neighbor Sharonica Watt said.

"I know he didn't mean to do it. I know he didn't mean to do it," friend James Washington said.