Two men allegedly involved in Boston police officer shooting in court Monday

Two men are expected Monday in a downtown Boston courthouse to face charges of having participated in the shooting of a Boston police officer in the South End Sunday afternoon, said officials.

The men were identified as 21-year-old Raquon Martin of Boston and 35-year-old Antoine Mack of Pawtucket, RI. They face many charges.

The name of the agent has not been published.

"Thank God it's a life-threatening injury," Police Commissioner William G. Gross said Sunday. "He was taken to a local hospital where he is being treated for this injury."

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The youth strike force officers of the department patrolled West Springfield Street shortly before 2 pm. On Sunday, they noticed a double parking car playing loud music, Gross said.

Three men who were sitting on the front stairs at 91 West Springfield Street made eye contact with the officers of the gang unit and immediately got up by "gripping the waist, characteristic of an armed man", said Gross.

The police tried to follow the young men into the building, but one of the three would have held the door to block the entrance of the police, according to the commissioner.

After the police penetrated inside the house, one of the young men shot at them, hitting an officer in the calf, Gross said.

After one of the men entered an apartment, SWAT agents and hostage negotiators came to the scene, Gross said. The police were finally able to detain the three men without further shots, he added.

Although Gross said Sunday that police had arrested three men, a police spokesman said Sunday night that the department had no information about a third suspect and the investigation was ongoing.

Around West Springfield Street, Sunday afternoon, several blocks were closed to traffic with yellow police tape, which neighbors and passersby watched as they tried to get an idea of ​​the situation. Unmarked and marked police vehicles, including large armored trucks, were posted in the area.

Vincent Peguero, who lives around the corner, said that he was out to smoke a cigarette when he saw a massive police response. He suspected that an officer had been injured, he said, and later he saw a policeman wounded on a stretcher with his boot and sock removed.

"Normally, when this number of policemen come out, it's a cop who was killed," he said.

Peguero said he had lived in the neighborhood for 20 years, and it is not uncommon to hear gunshots nearby, although it has become less common as the neighborhood has exchange.

"I'm a little used," he said. "Things are happening every day."

Mayor Martin J. Walsh visited the injured officer at the hospital on Sunday afternoon and, in a later statement, expressed his frustration with the shooting.

"Our police officers work hard every day to keep our residents safe, and this senseless violence will not be tolerated," said Walsh. "I wish a speedy recovery to the officer who has been injured and thank our first responders for their quick action today."

The injured officer is a veteran of the Boston Police Service for five years, according to Sergeant John Boyle, a spokesman for the police.

Mr. Gross said that he was "heartbreaking" when an officer is injured in the performance of his duties.

John R. Ellement, Globe Staff, contributed to this report. Jeremy C. Fox can be contacted at [email protected]. Follow him on Twitter @jeremycfox. Lucas Phillips can be contacted at [email protected].