PHILADELPHIA (AP) — Security video appears to show a Philadelphia transit officer shove a man holding a toddler against the wall and grab him by the throat as they argued over whether he paid the $2.25 fare.

The video shows the man swinging back at the officer and later being forcibly removed from the train still holding the small girl. He was then handcuffed on the platform and charged with resisting arrest.

The Southeastern Pennsylvania Transportation Authority video shows police speaking intermittently with 20-year-old Ellis Smith for about 15 minutes Thursday evening. The train eventually came to a stop and some rush-hour service was halted over the stalemate.

The veteran officer involved in the confrontation later told a supervisor he feared he would be disciplined if he walked away, SEPTA’s police chief said Friday.

“If a 16-year officer thinks they can’t step away from a situation that’s spiraling into something that might jeopardize the safety of a child, that’s on me. I never want a child’s safety to be jeopardized,” Chief Thomas Nestel said.

Nestel has waged an aggressive campaign against fare evaders, issuing 5,100 citations last year, on the theory that those passengers often cause other problems. He often posts their pictures on social media, and said the strategy has led to a significant drop in transit crime.

However, he recognized that fare evasion is not murder, and said his officers are not trained to grab people by the throat.

“We don’t want to be rolling around on a platform with every person we arrest for fare evasion,” Nestel said.

An internal investigation is underway. The officer involved in the shoving match was off Friday.

“I don’t know that I’ll be taking him off the street,” Nestel said.

There is no transit video of Smith jumping the turnstile or otherwise evading the fare because the north Philadelphia station where he entered is under construction, Nestel said. The information instead came from a cashier, he said.

However, a passenger’s video that caught some of his interaction with police was posted online and drew hundreds of thousands of views. A home number for Smith could not be determined Friday and it was not clear if he had a lawyer or had posted bail.

Fare evaders are typically removed, asked for identification and given a $300 citation, transit officials said.

The young girl — dressed in a pink dress and braids — is about 1 or 2 years old and believed to be Smith’s daughter, Nestel said. She was taken to her mother after Smith’s arrest.

“We can’t endanger the lives of little kids over a fare evasion,” Nestel said. “That’s unacceptable.”