Days after a viral video showed a dog owner, his pit bull, and a woman involved in a physical altercation on a 4 train, police have made an arrest. Brooklyn resident Ruben Roncallo was arrested on Thursday and now faces charges of reckless endangerment and assault.

A passenger on the train, Tahysi Kyng, said that the April 20th confrontation began when the victim, 22, asked Roncallo, who had let his leashed dog sit on a subway seat, to move his dog. According to Kyng, she told Roncallo, "The dog don't belong on the seat, that's an animal, people belong on the seat, put the dog on the floor."

Roncallo, 53, reportedly refused, and according to Kyng, the woman repeatedly pushed the dog off the seat. Roncallo allegedly allegedly responded by punching her, and then the dog bit her. Kyng started filming the incident as other subway riders were trying to pull the victim away from the dog.

"He was like, 'Don't touch my dog,' and he started hitting. They started fighting, and everybody tried to break it up. The dog latched onto her," Kyng recalled.

While the victim was able to walk off when the train car got to Wall Street, police say that she was treated for dog bites to her arm and foot at New York Downtown Hospital. Her mother said to WCBS 2 that she is still hospitalized.

Roncallo told reporters, "She attacked me first, she attacked me first," and insisted his dog was a service dog. An NYPD spokesman told Gothamist the arrest report characterizes Roncallo's dog is a service animal.

Dogs are only allowed on NYC subways if they are in a carrier or if they are service animals. The MTA specifically defines "service animals" as "a guide dog, signal dog, or other animal individually trained to perform tasks for the benefit of a person with a disability that such person is unable to perform due to such disability, such as guiding persons with impaired vision, alerting persons with impaired hearing to sounds, pulling a wheelchair, retrieving dropped items or providing rescue assistance. The term service animal does not include a therapy animal or animal used for emotional support."

Kyng's girlfriend, who also witnessed the incident, said, "That dog was not vicious. It was just an incident that could have been avoided."