The sister of the man fatally shot by police in Dorchester Friday said she found it hard to believe the allegations — that her 29-year-old brother, Peter Fanfan, had opened fire on Boston police officers while they were responding to a shooting.

“He wanted to get himself on his feet . . . [and] all of a sudden he’s going to pull a gun on police officers knowing all of the stuff going on with police nowadays? That doesn’t make any sense,’’ said Ruth Fanfan, 33, at her mother’s apartment in Jamaica Plain Sunday morning. “It’s kind of hard for me to swallow.’’

Fanfan, who had a lengthy criminal record, was killed on Stanwood and Laredo streets when officers returned fire.

Ruth Fanfan was with her mother, helping to plan her brother’s funeral.

“He was an awesome brother,’’ she said. “He always encouraged me . . . saying, ‘Do your best, no matter what you do. You can do anything.’ ’’

Those were his words to his sister after Ruth Fanfan told him she had lost her job.

She said her brother, one of four siblings, was working to turn his life around. He had found a job packaging salads and was working to move out of his mother’s apartment and get his own place. He was the protector, she said, the one who kept the family connected.

Ruth Fanfan said she couldn’t understand the events surrounding his death.

It was 10:35 a.m. Friday when police responded to a 911 call for a person shot. Police said two men had been shot inside a red three-story house at 107 Devon St. Police first spotted Fanfan, who was helping a wounded man down the street, officials said. An official with knowledge of the investigation said the officer believed he had found two victims.

Fanfan allegedly opened fire as the officer was getting out of his car, according to the official and to the Rev. Jack Ahern, pastor at St. Peter’s Church in Dorchester, who viewed a surveillance video and listened to audio of the fatal police-involved shooting on Saturday.

The officer shouted three times for the man to put the gun down and then returned fire, Ahern said. A gun was recovered at the scene, police said.

Fanfan, who was on probation and had been shot twice before, had 57 arraignments on his adult record and two gun convictions, according to an official with knowledge of the case and court documents. He had been evaluated twice at Bridgewater State Hospital for mental health issues.

Ruth Fanfan said her brother seemed fine when she saw him last week.

“He’s been trying to improve his life,’’ she said. “The details are a little off for me. I don’t want to say the police weren’t doing their jobs . . . it’s a dangerous job they do.’’

It was not clear what led to the shooting inside the home on Devon Street. Two men were injured inside the house, both were hospitalized and have not been identified by police.

The father of one of the men, Mitchell Taylor Sr., who owns the home where the initial shooting occurred said his son, Mitchell Taylor Jr., 31, was the victim of a home invasion and did not know Fanfan.

Taylor Sr. said two men came to the home while his son and another man were fixing a plumbing problem and asked for someone.

Taylor Sr., who learned about what happened from his son, said Taylor Jr. told the men they should not be in the house and that’s when things turned violent.

“They hit my son a couple of times and one of the men pulled out a gun,’’ Taylor Sr. said. The men began to fight for the gun, which eventually went off. Taylor Jr. was shot once in the arm, and one of the two men was hit by the same bullet, his father said.

The men continued to tussle for the gun and Taylor Jr. was then shot in his thigh and the bullet struck his femur, shattering the bone, his father said. Taylor Jr. collapsed and one of the men then shot him again in the other leg. A tenant said he called police after hearing the commotion and finding Taylor Jr. lying on the basement floor.

“It was a home invasion,’’ Taylor Sr. said. “My son was fighting for his life.’’

But the shooting inside the home did not appear to be random, said Officer Rachel McGuire, a Boston police spokeswoman, on Sunday.

Taylor Sr. said his son remains hospitalized and was set to undergo a second surgery Sunday. “My son didn’t know those people,’’ he said.

Taylor Sr., an electrical engineer and veteran who served in the Air Force, said he rents the house to veterans and none of his tenants appeared to know the men.

“It’s too bad about the gentleman; he’s someone’s son,’’ Taylor Sr. said of Fanfan. “The police did the right thing. People like that should not be walking out on the streets.’’

There were two fatal Boston police-involved shootings in 2015.

Suffolk County District Attorney Daniel F. Conley said on Saturday that the investigation into Friday’s shooting was still ongoing and it was too soon to say whether it was justified. His spokesman said on Sunday that no charges have been brought against anyone at this time.

Jan Ransom can be reached at jan.ransom@globe.com. Follow her on Twitter at @Jan_Ransom.