A 17-year-old Idaho boy with autism who was shot by police last weekend as he had a knife has been declared brain-dead, his aunt said Friday.

Victor Perez, who his family said is autistic and has cerebral palsy, was shot nine times by police officers in Pocatello after they responded to a neighbor’s call about someone with a knife on April 5, officials said.

Perez’ aunt, Ana Vazquez, confirmed to NBC News in a text message late Friday that the teenager was declared brain-dead.

NBC affiliate KPVI of Pocatello and other local outlets reported the condition earlier Friday, and the mayor of the city of around 56,000 said in a statement that he was saddened by the news.

“Our thoughts and prayers are with the family and loved ones during this unimaginably difficult time. We recognize the pain and grief this incident has caused in our community,” Pocatello Mayor Brian Blad in a statement.

Perez was shot by police officers who responded to a 911 call at around 5:22 p.m that said there was someone with a knife and that others appeared to be trying to get the weapon from him, audio played by police following the shooting showed.

Vazquez said that there was a family barbecue, that family members had hidden a knife and that Perez has found it. She said that Perez’ sister was trying to get the knife from him, but that they were not in danger and there the 17-year-old was not posing a threat to them.

Police Chief Roger Schei said that officers repeatedly ordered Perez to drop the knife and that Perez stood up and advanced toward them while holding the weapon.

He said at a Monday news conference that the officers in situations like the one on April 5 have to make fast decisions not only about their own safety but the safety of others.

“In this case, two individuals were within a few feet of an armed, non-compliant individual,” Schei said at a news conference Monday. “The risk was immediate, and the situation rapidly evolving.”

Vazquez said that officers did not take the time to ascertain the situation before firing on Perez. She said the teenager was in a mental health crisis.

A bystander recorded the shooting on video, and that shows officers ordering Perez to drop the knife, and Perez struggling to stand with the knife and then moving towards officers before they fire. In the video, there appears to be a chain-link fence between the officers and Perez.

There are criminal and internal investigations being conducting about the incident, the mayor’s office said. The Eastern Idaho Critical Incident Task Force is conducting an external investigation, it said.

The four officers involved were immediately placed on administrative leave after the incident, which is standard procedure after a shooting, the city said.