CHICAGO – A man was charged with first-degree murder after police said he pushed a Marine veteran into the path of a passing train.

Mamadou Balde, 29, died after being "punched and pushed" onto the tracks of a downtown CTA red line platform on the evening of April 7, according to the Cook County state's attorney.

Ryan Munn, 18, was arrested three days later and charged with first-degree murder, the Chicago Police Department said.

The incident was captured on surveillance video from multiple angles, according to the bond letter provided by the state's attorney.

The video shows Balde "appearing to be intoxicated" and occasionally approaching other people on the platform of the downtown Jackson station, according to the document. Munn and an unidentified man were hanging out on the platform at the time.

Balde approached Munn's friend, whom police have not identified, and the two had a "brief conversation," according to the document. As a southbound train pulled into the station, Balde, smiling and laughing, put up his fists as if he were "jokingly putting up his dukes to fight."

The unidentified man punched Balde in the face, pushing him backward toward the train, the document said. As the man continued to punch Balde and push him, Munn allegedly joined in.

Balde was pushed against the train and fell between two CTA cars, according to the document. The train began to move, and Balde suffered multiple blunt force injuries. Munn and the other man left the station.

Balde was pronounced dead by the Cook County Medical Examiner's Office.

Munn was arrested three days later at his home on the city's North Side.

"I am mad," Al Balde, Mamadou Balde's father, told The Chicago Tribune. "This guy gave his life for his country, and three people throw him on the train."

Police initially reported that Munn was at the station with two other people, but descriptions of surveillance video describe only Munn and one other person. USA TODAY has not reviewed the video, which was not provided by police.

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According to the Tribune, Balde lost his mother to cholera when he was 3 and moved to the USA from West Africa when he was 9. He joined the Marines when he was 18 and served two tours in Afghanistan.

Munn told officials he was only trying to hurt Balde and push him onto the ground, not onto the tracks, according to the document.

Video stills of Munn and the man were shown to district police officers, who recognized both defendants from prior contacts, according to the document. Those officers provided the defendants' names to detectives, who placed them each in photo arrays. Three witnesses positively identified both Munn and the man.

Police have not publicly identified the other man, and it was not immediately clear whether there was a warrant out for his arrest. Area detectives were investigating.

Munn is held without bail in Cook County Jail and is to appear in court Friday.

This article originally appeared on USA TODAY: Chicago man charged with murder after allegedly pushing man into train