A police officer has been arrested in the off-duty beating of a 15-year-old high school student, the Chicago Police Department said Sunday.

Robert Gallegos, who is charged with aggravated battery, appeared on closed-circuit television Sunday afternoon in a Cook County courtroom, where a judge set bond at $100,000.

The officer, who was assigned to the department's mass transit unit, was arrested on Saturday, four days after the Juarez High School student suffered a broken jaw and other injuries in the attack, according to a police statement.

Gallegos' son was involved in a "verbal altercation" with the teen, which allegedly prompted the attack, according to police. Prosecutors told the court Gallegos attacked Eduardo Cardenas in an alley as the teen walked with two young women, throwing the boy against a garage and then punching him in the face. They also said he kicked Cardenas after he fell to the ground.

A lawyer representing Gallegos at Sunday's hearing, Jim Thompson, said he disagreed with the prosecution's version of events, saying Cardenas had threatened Gallegos and his family. As he left the courtroom, Thompson declined to comment to reporters.

Gallegos, who was assigned to the department's mass transit unit, has been relieved of his police powers, according to a police department news release. A call seeking comment was placed with a department official.

The dispute is the latest in a series of alleged beatings by off-duty Chicago police officers.

Earlier this month, officer Anthony Abbate pleaded not guilty to charges he beat a female bartender and then threatened to arrest bar employees and customers in a failed attempt to suppress a video of the attack.

Three other officers were charged in an another alleged fight with four businessmen at a city bar that authorities say was caught on videotape.

The department has been criticized for the way the incidents were handled, including that police acted too slowly to arrest and charge the suspects. Police Superintendent Phil Cline has since announced his intention to retire.