(ABC NEWS) -- Two Boston police officers were credited this morning with dragging two critically wounded colleagues out of the line of fire after a suspect now identified as Kirk Figueroa shot them Wednesday night as they responded to a domestic incident.

"Domestic calls are the most volatile," Boston Police Commissioner William Evans said at a news conference today. "You never really know what you’re walking into."

The injured officers received potentially life-saving first aid, including a tourniquet, as one officer pressed his hand over a wound to slow the bleeding, Evans said.

The emergency first aid was "instrumental" in getting the injured officers to the hospital quickly, he added.

“Our officers are out of surgery and recovering,” the Boston Police Department said on its Twitter account this morning. “They remain in critical condition at this time. Please continue to keep them in your prayers.”

Figueroa, 33, is suspected of shooting the officers after they responded to a 911 call about 10:51 p.m. for the domestic incident with the possibility of a person being armed with a gun. Several other officers responded and went inside the residence, where they exchanged fire with and eventually killed the suspect, police said.

No additional information is available at this time about the suspect.

2 Boston Police Officers 'Extremely Critical' After Being Shot in 'Domestic Incident Gone Bad'

Commissioner Evans said other officers were prompted to respond after they heard screaming of shots fired and officers down on the radio shortly after the two injured officers initially arrived and entered the home.

The suspect had body armor and was armed with an assault rifle, Evans said.

The two wounded officers, both male veterans with a combined 40 years on the force, were transferred to Massachusetts General Hospital in "extremely critical" condition" where they underwent blood transfusions and surgery. Nine additional responding officers suffered minor injuries or were dealing with stress and trauma, according to the police commissioner.

ABC News' J.J. Gallagher, Matt Foster and Matt Stone contributed to this report.