Tapiwa Musonza, 28, shown in 2016, had charges against him dropped in an incident during which he was shoved by a Metro police officer and then hit by a stun gun. Members of the D.C. Council blamed the officer for escalating an impassioned discussion into a violent confrontation. (Family photo)

Prosecutors in the District on Monday dropped all criminal charges against a man who was shoved by a Metro Transit Police officer and then hit with a stun gun as police accused him of interfering with the questioning of a handcuffed teenager at the U Street station.

Tapiwa Musonza, 28, was freed from jail as activists, members of the D.C. Council and his family blamed the officer for escalating an impassioned discussion into a violent confrontation. A bystander captured the incident on video that spread over social media.

“It’s terrible,” said Musonza’s mother, Precious Musonza, who lives with her son in Suitland, Md. “I was scared when I saw this. I thought the next thing they would do was pull out a gun and say my son was armed.”

Metro police charged Musonza with resisting arrest, obstruction of justice and assault on a police officer. The U.S. attorney’s office on Monday chose not to pursue the case but did not provide an explanation. Musonza could not be reached for comment.

Six members of the D.C. Council expressed concern over the incident, and at least two called on Metro’s police chief, Ron Pavlik, to suspend the officer during an internal investigation that began Sunday. Metro kept the officer on full-duty status. A Metro spokesman did not respond to a request to interview Pavlik.

“The video leaves little doubt in my mind that what happened was unacceptable,” said council member Brianne K. Nadeau (D-Ward 1), who represents the area where the incident occurred. Kenyan R. McDuffie (D-Ward 5) said that “it erodes public confidence in policing.” And Charles Allen (D-Ward 6), who chairs the public safety committee, said, “From what I saw, it was an officer who escalated and created a dangerous situation. It’s unacceptable, and it’s not how we want policing in the District of Columbia.”

Musonza, who graduated from Howard University three years ago with a degree in finance, was returning from visiting the U Street entertainment strip when the incident unfolded Saturday evening, according to this mother.

In the station, Musonza began conversing with two transit officers as they stood over the teenager, one of several stopped after a complaint of youths threatening people with sticks, according to a police report made public by Metro. Police said no victims were found and none of the juveniles were charged.

On the video, Musonza appears to engage in a verbal exchange with the two officers, one a supervisor, who do not appear bothered by the interaction as they stand over the youth on a bench. Musonza is standing on the other side of the bench.

A third officer, wearing a yellow “K-9” vest and identified in a police report and by a Metro spokesman as Jonathan E. Costanzo, approached Musonza and pushed him back. Musonza extended his arms outward, his palms visible, and took a small step toward the officer. Costanzo shoved Musonza with his right hand. Musonza flailed his arms. The two separated, and the officer fired his stun gun as a bystander yelled, “Not necessary, not necessary.”

The video was taken from behind the officer, and not all portions of the interaction are clearly visible.

Constanzo, reached by phone, declined to comment.

The police report says the first officer who responded to the call requested help and indicated he was “surrounded by a large crowd” as he tried to detain several people on the platform. The report says that Costanzo was one of the officers who came to help and that he was asked to move Musonza away from the bench. The report says Musonza refused the order. The commands were not audible on the video.

Costanzo “attempted to push him back from the scene to create space from the preliminary investigation,” the report says, adding that Musonza “pushed back with his hands attempting to get closer to the other officers.” When Costanzo drew his stun gun, the report says, Musonza replied, “Go ahead tase me,” and “took a combative stance by clinching his fists and squaring up.”

The video does not appear to show Musonza in a fighting stance.

The reports say Costanzo used his stun gun twice, to no effect, and then he and another officer struggled to subdue Musonza. The report says Musonza became prone only after another officer, identified as J. Ditrick, pressed a stun gun to Musonza’s leg and deployed it, a technique called “drive stun.”

McDuffie, the council member, said it appeared to him from watching the video that Musonza “had his hands extended in a nonthreatening manner.” He said removing the officer from the street would “inspire confidence that Metro Transit Police is taking this situation seriously and transparency.”

Musonza’s mother said her son immigrated in 2010 from Zimbabwe and became a U.S. citizen. He lives with her in Prince George’s County, where he is trying to launch a start-up company to help college students move on and off campus, she said.

Precious Musonza, a 54-year-old caregiver, said she thought that the police had “overreacted” and that she felt there was insufficient communication among the officers her son was talking with and the officer who pushed him away.

“Emotions were high, but my son doesn’t fight,” she said. “He likes helping people. That’s why he was talking to that little boy. . . . He was trying to do the right thing, and the police thought it was the wrong thing.”

Jennifer Jenkins, Keith L. Alexander, Fenit Nirappil and Steve Thompson contributed to this report.