D.A. Reveals Details of Shooting of Det. Mario Oliveira, Says Return Fire Was Justified

The Middlesex District Attorney’s Office issued the following statement Friday detailing the circumstances of the Nov. 2 and the subsequent investigation:

The Middlesex District Attorney’s Office and the Massachusetts State Police assigned to the Middlesex District Attorney’s Office have conducted an investigation into the facts and surrounding circumstances of a shooting by an on-duty officer with a department issued firearm that occurred on November 2 on Gibbens Street in Somerville. 

The investigation into the legal justification of the shooting by the officers included a thorough review of interviews of witnesses at the scene and the responding Somerville Police officers, photographs of evidence gathered from the scene, ballistics and crime scene forensic reports, radio transmissions and 911 calls, police reports, witness statements, and medical examiner information. 

That investigation revealed the following facts:

In October 2010, authorities were conducting an investigation into the activities of Matthew Krister, who had purchased eight firearms in New Hampshire over the course of ten days.  On October 19, Matthew Krister met with detectives from Somerville Police and the Bureau of Alcohol, Tobacco and Firearms at the Somerville Police Station.  During that interview, Krister said that he was residing at 6 Gibbons Street in Somerville.  Police conducted a subsequent investigation and learned that Krister admitted that he had purchased eight handguns in New Hampshire from October 8 to October 18, 2010, and that he had sold six of them to gang members.

On the evening of November 2, 2010, at approximately 5:30 p.m., detectives drove by Matthew Krister’s residence at 6 Gibbens Street in Somerville in an attempt to locate him and arrest him on a warrant they had obtained for him on firearm charges.  Once Krister’s vehicle was located in the driveway of the residence, additional officers arrived and assisted the detectives in surveillance of Krister’s residence, with the intention to arrest Matthew Krister when he came out of his residence and before he was able to drive away from the house.  It was dark out at the time, although streetlights lit the area. 

Two law enforcement personal, ATF Agent Brian Higgins and Somerville Police Detective Mario Oliveira, then got out of their vehicle and approached Krister’s residence, with their badges prominently displayed around their necks.  At the same time, Krister walked out of his house with one hand in his pocket and a backpack over the opposite shoulder.  As Krister got into his vehicle and closed the driver’s side door, Detective Mario Oliveira walked up to the door and opened it.  Simultaneously, Agent Higgins drove up to Krister’s vehicle to prevent him from driving away.  Detective Oliveira and the ATF Agent were known to Krister as police officers from their previous interactions.

As Detective Oliveira stood in the open doorway of Matthew Krister’s vehicle, Detective Oliveira held his firearm in his right hand, grabbed Krister by the shoulder with his left hand, and ordered him to get out of the vehicle.  Agent Higgins then got out of his vehicle and stood on Detective Oliveira’s right side.  He also had his firearm out and pointed at Krister. 

Matthew Krister did not get out of the vehicle.  Instead, he moved his body away from Detective Oliveira so that the detective lost his grip on him.  Again, Detective Oliveira reached into the car, grabbed Krister, and ordered him out of the vehicle.   Suddenly, and without warning, while Detective Oliveira was holding onto him, Krister pulled out a loaded 9 mm semi-automatic pistol and pointed it at the detective.  Matthew Krister then began shooting that firearm directly at Detective Oliveira’s body at close range.  Detective Oliveira was shot five times, striking him in the chest, stomach and right arm.  Detective Oliveira said, “I’ve been shot” and fell to the ground.

After Matthew Krister began shooting Detective Oliveira, ATF Agent Higgins returned fire at him.  Somerville Police Sergeant Joseph McCain, who was standing in front of the driver’s side of Krister’s vehicle, began to fire at him through the windshield.  Somerville Police Sergeant Gerald Reardon, who was standing on the passenger side of the vehicle, also fired at Krister through the closed, passenger-side window. 

Agent Higgins pulled Detective Oliveira across the street to get him away from the gunfire.  Agent Higgins then went to the back of Krister’s vehicle and fired at him through the rear window.  Sergeant McCain approached the driver’s side of the vehicle, saw that Krister had laid down across the front seat to get out of Sergeant McCain’s line of fire and was still holding the firearm with which he had just shot Detective Oliveira.  Sergeant McCain then saw Krister raise the firearm and point it in the direction of the police officers, and Sergeant McCain fired at him to prevent him from firing his firearm at the officers again.   

Matthew Krister was transported to Somerville Hospital where he was pronounced dead.  The Office of the Chief Medical Examiner conducted an autopsy.  The cause and manner of death were determined to be homicide resulting from seven gunshot wounds of the torso and extremities with injuries to the lungs, liver, aorta and spine. 

Detective Oliveira was transported to Massachusetts General Hospital where he was treated for his five life-threatening gunshot wounds and thereafter hospitalized for nine days.  Two projectiles were recovered from Detective Oliveira’s body at the hospital.  At least one of those projectiles was matched to Matthew Krister’s firearm.  As of the date of this statement, Detective Oliveira is still out of work as he continues to recover from his extensive injuries.

Our investigation further revealed that in the weeks leading up to this incident, Matthew Krister had called an ex-girlfriend and told her that he was in trouble for gun trafficking with the ATF and that he thought he was going to go to jail for a long time.  He also said that he thought the police were going to come looking for him and if they did, he would get into a shoot out with them.

Upon a completion of this investigation and review of all available information and relevant evidence, the conclusion of this office is that the actions of the officers in initially returning gunfire once Krister fired at and shot Detective Oliveira multiple times were justifiable under the law to effect lawful objectives, bring the incident under control, and protect the lives of Detective Oliveira and others. 

Similarly, the additional return fire that took place once the police officers checked on the status of the suspect and the suspect raised his gun again at the police officers, was also justifiable under the law to effect lawful objectives, bring the incident under control, and protect the lives of Detective Oliveira, the police officers involved and others. 

The intentional, calculated and potentially deadly actions of the decedent placed the lives of all officers involved, and others, in extreme danger of likely grievous bodily harm or death.  The officers who discharged their firearms did so to save Detective Oliveira’s life, their own lives, and possibly the lives of others in the vicinity of the shooting.

Having made our determination under the law regarding the legal justifiability of the shooting by the involved officers, we have, per the protocol of the Middlesex District Attorney’s Office, referred the matter back to the Somerville Police Department so that it can perform whatever internal administrative review of the incident it deems appropriate.