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. "We have not been able to establish that."

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.

"The question is, what degree of charge are we filing?" he said. "Are we going to be able to establish the seizure disorder that caused his death is directly related to the punches thrown in the school yard that particular day?"

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, pending the results of tests on Bailey's brain.

The altercation was captured on video.

"It looks to me that he did not retaliate, that he covered his face when there were two to three punches thrown in that very brief incident," Whelan said.

Bailey's family did not return phone messages Tuesday. An anti-bullying page on Facebook was set up in his memory.

A Roman Catholic, he was to be confirmed on March 18. Instead, he was given last rites on his birthday.

"When I gave him last rites on Saturday, he was looking at me and reaching for me," the Rev. Thomas Sodano, pastor of Saint Joseph Church, told The Philadelphia Inquirer.

Sodano said a girl who had told him she witnessed the scuffle said O'Neill was backing away and trying to avoid a fight.

"Anybody who knows him knows he's not that kind of a kid," Sodano said.

Bailey will be buried Saturday after a service at the church in Collingdale, Delaware County.