Subscribe to Breaking News emailsYou have successfully subscribed to the Breaking News email.Subscribe today to be the first to to know about breaking news and special reports.Breaking News EmailsGet breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.The New York attorney general opened an investigation Thursday into the fatal shooting of a black Brooklyn man who police believed was pointing a gun at them — but who was actually holding a piece of pipe with a knob at one end.Saheed Vassell was mortally wounded on Wednesday afternoon when at least three plainclothes and two uniformed officers fired 10 shots at him, police said. He was pronounced dead later at Kings County Hospital.“The Attorney General’s Special Investigations and Prosecutions Unit has opened an investigation into the death of Saheed Vassell,” Amy Spitalnick, spokeswoman for Attorney General Eric Schneiderman, said in a statement. “We’re committed to conducting an independent, comprehensive and fair investigation.” Saheed Vassell points a pipe at a bystander Wednesday in Brooklyn in surveillance video. via WNBCIn New York state, the attorney general has the power to act as a special prosecutor in cases where police officers kill unarmed people.New York City Mayor Bill de Blasio called Vassell’s death “a tragedy by any measure” but stopped short of blaming the police. He said the responding officers were unaware that he had “a profound mental health problem.””People in the community thought he had a weapon and was aiming at residents,” he said Thursday. “There is a lot more we need to know.”The NYPD has not identified any of the officers involved in the shooting.But Vassell’s family and friends told The Daily News that the slain man was a “quirky neighborhood character” who was widely known to be bipolar and who had been hospitalized multiple times before for mental issues — often after crossing paths with police.“Every cop in this neighborhood knows him,” local resident John Fuller told The New York Times.The death of the 34-year-old Jamaica-born welder happened on the 50th anniversary of Dr. Martin Luther King’s assassination. And outraged the black residents in the Crown Heights neighborhood, some of whom carried Black Lives Matter signs, yelled “Murder!” at the officers guarding the scene of the fatal shooting.Vassell was killed less than three weeks after police in Sacramento, California fatally shot a 23-year-old black man named Stephon Clark in the mistaken belief he was holding a gun. It turned out to be a cell phone. The metal object that police mistook for a firearm lies on the sidewalk at the scene of the fatal shooting in Brooklyn on Wednesday. New York Police Department / via APIn the California case, body cameras captured the moment when Clark was cut down by a fusillade of 20 shots.None of the New York City police officers who fired on Vassell were wearing body cameras, NYPD Chief of Department Terence Monahan said after the shooting. He insisted the doomed man threatened the officers.“The suspect then took a two-handed shooting stance and pointed an object at the approaching officers,” Monahan said, holding a surveillance photo of a blurry figure standing beside an ice machine with his arms outstretched.The chain of events that ended with Vassell dying at the corner of Utica Avenue and Montgomery Street began around 4:40 p.m. Wednesday when police responded to three 911 calls that described a black man in a brown jacket waving what the witnesses mistakenly described as a silver gun, Monahan said.A surveillance image obtained by NBC New York showed Vassell running and pointing the pipe at a person on Utica Avenue.Witnesses said the officers jumped out an unmarked car and started shooting without warning.“It’s almost like they did a hit,” 40-year-old Jacob Hinds told The Daily News. “They didn’t say please. They didn’t say put your hands up, nothing.”So far, the NYPD has not said whether the officers who fired the fatal shots warned Vassell first.His 15-year-old son, Tyshawn, said there was no reason to kill his dad.“He cared for everybody,” he told The Daily News. “If you saw him, he’d always be in a laughing mood. You would never catch him down.”Breaking News EmailsGet breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.Breaking News EmailsGet breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.MORE FROM newsHave feedback?How likely are you to recommend nbcnews.com to a friend or colleague?0 = Very unlikely10 = Very likelyPlease select answerIs your feedback about:ContentDesignOtherPlease select answerLeave your email if you’d like us to respond. (Optional)Please enter a valid email addressThank you!Your feedback has been sent out. Please enjoy more of our content.We appreciate your help making nbcnews.com a better place.