EARLY, Texas– A 10-year-old boy was arrested for sexually assaulting a fellow student on an Early ISD school bus last month., police said.

Early Police Chief David Mercer said the students were riding the bus after school on February 6 when the driver got off and went outside to assist a handicapped student.

While he was gone, the 10-year-old suspect sexually abused a 9-year-old girl, according to police.

The girl’s mom told KTAB and KRBC they were the only students left on the bus because their classes got in trouble and they had to stay on campus late.

After an investigation that included a forensic exam, the 10-year-old was arrested and charged with sexual assault. His case was being processed through the juvenile justice system.

DNA evidence was taken from both the victim and the suspect and was currently being processed at the lab.

Police said the bus driver will not be facing criminal charges, based on the information they have at this time.

This case was still under investigation Tuesday.

(KTAB/KRBC contributed to this report)