A district attorney investigating the death of a 12-year-old suburban Philadelphia student after a brief altercation in the school yard said Tuesday the boy was punched two or three times in the face and did not fight back.

Delaware County District Attorney Jack Whelan said he’s found no evidence that Bailey O’Neill had been bullied by his assailant in the days and weeks leading up to the Jan. 10 scuffle, tamping down widespread speculation to the contrary. Bailey’s family has said the sixth-grader was bullied at school.

“We’re having trouble showing there was bullying, as a course of conduct as we define it, intimidation or harassment between these two boys over a course of time,” he told The Associated Press.

Bailey died Sunday, a day after his birthday. The sixth-grader’s family said he suffered a concussion, broken nose and other injuries in the attack at Darby Township School. Doctors induced a coma after he began having seizures.

Whelan said charges against the 11-year-boy who hit Bailey are likely, ranging from harassment and simple assault to involuntary manslaughter.

A decision on charges will be made after Whelan gets a ruling from the Philadelphia Medical Examiner’s Office on the cause and manner of Bailey’s death. A spokesman for the medical examiner said it will be a few weeks before a ruling is issued.