The Los Angeles County District Attorney's Office dismissed a child abuse case against a former teacher who was seen on video last year repeatedly punching a high school student who called him a racial slur.

Marston Riley, 65, was arrested in November 2018 after cellphone footage captured at Maywood Academy High School showed him striking a 14-year-old boy several times before another adult intervened.

Riley worked at the school in Maywood, a small city southeast of downtown Los Angeles, as a music teacher. He was released from jail after posting bond.

Prior to the fight, the teenager confronted Riley for allegedly saying negative things about him. The video showed the boy cursing at Riley, who is black, and calling him a racial slur.

The teen was hospitalized for "moderate injuries" after the fight and then released.

A spokesperson for the D.A.'s office said a motion was filed on Monday to drop a misdemeanor corporal injury charge against Riley and the court granted it. The decision to dismiss the case was based on a number of factors, including Riley not having a prior criminal record and not getting into any trouble after the altercation.

The prosecutor also took into consideration "the facts and circumstances surrounding the incident," Riley's age, his completion of a 10-week anger management course and his being forced into early retirement from his job.

Following the November 2018 incident, community members raised more than $90,000 for Riley.

In a Facebook video statement Wednesday, Riley thanked his supporters and said because the case was dismissed he could explain what happened with the student.

Riley said the incident began after he told the teen that he was not wearing the proper school uniform. The teacher claims the student became upset and was using "foul language." Riley said the boy called him the N-word several times.

Riley said he initially kept calm and asked the student multiple times to leave the room.

"The less I did, the more violent he got," Riley said, adding that the teen hit him with a basketball.

"That's when the physical altercation happened," he continued. Riley said the fight reminded him of another incident in which three students allegedly jumped him. "My thinking at that time was this ain't going to happen to me again," he explained.

The fight ended after a school security guard and other students in the room separated Riley and the teenager.