The fatal shooting of a knife-wielding man by a state trooper on a footbridge over Storrow Drive near Boston University in 2015 has been deemed justified, the office of Suffolk County District Attorney Daniel F. Conley announced Wednesday.
An investigation found that Trooper Andrew Patterson acted in self-defense when he shot Santos Laboy, 44, who was approaching him with a knife on the Silber Way Footbridge, even as Patterson was backing away, Conley said in a report.
“Trooper Andrew Patterson fired his weapon in a lawful and proper exercise of self-defense and defense of others . . .” the report stated.
Shootings by police are routinely investigated by district attorneys, who determine whether the use of deadly force was warranted. After each police-involved shooting the district attorney’s office releases a report on its findings.
A Spotlight report last year found that in every fatal police shooting examined by the Globe, the use of deadly force was deemed justified.
Conley said he met with Laboy’s family Wednesday to discuss the findings. The family, which could not be reached for comment, said in the past that Laboy had a long history of untreated mental illness and had been in and out of prison.
The June 19, 2015, confrontation began when Boston University police officers saw Laboy on the Esplanade and believed he fit the description of a man with outstanding warrants on harassment charges. Investigators believed Laboy had been slipping lewd photographs under the door of the Laundry Basket on Beacon Street in the Fenway.
According to the prosecutor’s account, when the officers approached, Laboy led them on a chase along the footbridge and then into traffic on Storrow Drive, where he tried to get into several vehicles while brandishing a knife. He also threatened to “stick” one officer with his knife, according to the report.
Officers tried to stop Laboy with pepper spray, by blocking his path with a cruiser, and by attempting to knock him to the ground.
Patterson had been working nearby when he heard Boston University police request assistance. He drove over and saw Laboy waving a knife at the officers before jumping over a guardrail and into outbound traffic, according to the report.
Once back on the Esplanade, Patterson drew his weapon and ordered Laboy to “stop” and to “drop the weapon” at least 15 times, the report said. But Laboy continued toward him with a knife with a three-inch, double-edged blade.
Laboy allegedly crouched and told Patterson, “I’m not going down,” then began to approach. Patterson fired four shots, killing Laboy.
Police said they found a second knife in Laboy’s gym bag, along with sexually explicit photographs that appeared to be identical to those found at the Laundry Basket.
Based on interviews with officers, witnesses, video footage, police radio transmissions, and a review of other materials from State Police, Boston police, and Boston University officer, Conley concluded criminal charges were not appropriate.
“I conclude that Trooper Patterson’s fear for his life was entirely reasonable,” Conley wrote in the report.
The superintendent of the State Police, Colonel Richard D. McKeon, said his department was confident that Patterson “acted appropriately, and in defense of himself and others.”
“As police officers, we never want to have to fire at a suspect,” McKeon said. “Nonetheless, in certain circumstances, when an advancing armed suspect does not comply with orders to drop his weapon, or if no other means of de-escalation are possible, doing so is necessary to protect officers and bystanders.”
Laboy survived a 2009 confrontation with Boston police, who said he was armed with a three-foot samurai sword. Laboy had said that he planned to kill people, according to his attorney at the time. Laboy smashed cars, including police cruisers, and begged officers to shoot him. He was sentenced to five years in prison, followed by five years of probation.