In the aftermath of a police-involved shooting that left a man dead and sent a valet to the hospital with a gunshot wound, the mother of the man killed by police insisted that her son didn’t own a lethal firearm.

“There’s no way he was shooting a gun at anyone,” said Barbara Root, whose 41-year-old son Juston Root of Mattapan was killed by police on Route 9 in Brookline Friday morning, after sparking a pursuit that began outside Brigham & Women’s Hospital in Boston.

The situation started at 9:21 a.m., when officers were called to the intersection of Vining Street and Fenwood Road near the hospital for a report of a man with a gun, according to Boston Police Superintendent-in-Chief Gregory Long.

Long said that when the cops arrived, they were pointed to what appeared to be an armed man, who then “pulled out and pointed at the officers what appeared to be a firearm.”

According to Long, police fired their weapons at the suspect, later identified as Root, but it wasn’t clear if they hit him or if he returned fire.

As the shooting unfolded, a 49-year-old valet at the hospital was shot and seriously wounded, though police said it is unclear who fired at him. He is currently in stable condition.

“I thought I was about to see a man die,” said Justin Heitmann, who was waiting to see a doctor at the Brigham. “My stomach dropped. I was in shock.”

Long said the suspect then physically assaulted one of the officers — leaving the officer mildly injured — got into a car and drove off, leading police on a chase into Brookline before he ultimately struck several other vehicles and came to a stop.

He was shot after he exited the car and pulled out the apparent gun again, which officers repeatedly told him to drop, Long said. He was pronounced dead at the hospital.

Long said it’s not clear if he ever fired his gun.

However, Barbara Root told the Herald on Saturday her son doesn’t own a handgun, only a BB gun, and that she plans to hire a private investigator in order to “find out the truth ourselves.”

“He was my best, best friend,” Barbara Root said.

The grieving mother, furious about her son’s death said that Juston Root was a kind man who’d gotten mental-health issues under control years ago.

“They’re putting out this image of, ‘Oh, he has a mental illness — oh, he’s killing people,’ ” Barbara Root said. “It’s just not true. They’re just stupid, stupid jerks.”

A spokesman for BPD said the investigation into the shooting is in its early stages and would not comment when asked if Root was definitively carrying a firearm.