Police arrested a 7-year-old boy, handcuffed him and hauled him down to the station house on a charge of riding a motorized dirt bike on a sidewalk.

Then, according to his mother, Gerard Mungo Jr. was handcuffed to a bench and interrogated before being released to his parents.

"They scared me," Gerard told The Baltimore Examiner before breaking down in tears.

Mayor Sheila Dixon apologized Friday for the arrest, and police commissioner Leonard Hamm said it would be investigated internally.

The arrest came after an officer saw Gerard riding his dirt bike on the sidewalk in east Baltimore on Tuesday, police spokesman Matt Jablow said. Hamm, citing the internal probe, declined to discuss how the rest of the incident unfolded.

Kikisa Dinkins said her son was sitting on the bike with the motor off on the sidewalk when an officer grabbed him by the collar and pulled him off.

"I told them to let go of my baby," Dinkins said. "Since when do you pull a 7-year-old child by his neck and drag him?"

Dinkins said she called for a police supervisor to intervene, but the confrontation continued to escalate after the supervisor arrived.

"They started yelling at him, 'Do you know what you did wrong, son?'" Dinkins said. "He was so scared he ran upstairs."

Police arrested Gerard and confiscated the bike.

Dinkins said officers fingerprinted him and took his mug shot. Hamm could not confirm that and said those actions would not have been normal procedure in a non-felony case.

Dinkins said the arrest scarred her son. "This has changed his life," she said. "He'll never be the same."

The Police Department's zero-tolerance arrest policy—begun under former Mayor Martin O'Malley, who is now Maryland's governor—has drawn complaints that such arrests occur most often in poor, black neighborhoods. Gerard is black.

Hamm said the officer had the option of talking with a parent or confiscating the bike. He said that although the city is concerned about nuisance dirt bikes, the arrest "was not consistent with my philosophy of trying to solve problems in the neighborhoods."

The mayor, who appeared Friday with Hamm, said she also planned to look into the case.

"It is clear to me that the arrest was wrong, that the officers on the scene should not have arrested the child, and on behalf of the City of Baltimore I apologize to the boy and his parents," Dixon said.