NATALIE DALTON can't shake the image of her 6-year-old son on a surveillance video running out of the school bathroom struggling to put his pants back on.

It's ingrained in her memory, she said, as it is for her son, Ernest Key, a kindergartner at Lea Elementary in West Philadelphia, who she said was sexually assaulted by two boys during an after-school program in April.

The surveillance video from April 23 showed her son leaving the cafeteria unescorted, which is against school policy, and going into a bathroom nearby, she said.

About 10 seconds later, two boys, who are in third and fifth grades, went in after him.

The boys then forcibly removed Ernest's pants and underwear, then rubbed against him, said Fernando Gallard, a district spokesman, who read from the school's incident report.

Dalton said they then ran out of the bathroom.

Ernest did not report the incident that day and school officials couldn't confirm that the incident occurred, Gallard said.

"The student changed his story several times," Gallard said.

Dalton called the school several times, but after her messages weren't returned, she went there to speak with the principal, Lisa Bells Chiles, but was unsuccessful.

When Dalton returned, the mother of one of the accused bullies happened to be in the school's front office. She confronted the mother and a fight broke out.

Days later, the students were suspended for two days, but district officials wouldn't say whether the bathroom incident was the reason for the suspension.

"He's been in the school since he was 3," Dalton said. "He's the victim in this case and a fight had to break out for them to do anything about it."

She filed a report with police Special Victims Unit, which decided with the District Attorney's Office not to make any arrests.

Dalton's son now gets counseling twice a week. She has filed a private criminal complaint and is waiting for mediation between her and one of the boys' parents, she said.

Dalton said she's not satisfied. "He doesn't want to go into the bathroom by himself," she said.

"He's terrified of the bathroom. If they could do this to my son, they could do it to someone else's child," she said.