New York (CNN) -- Federal prosecutors will investigate the case of a white police officer who shot and killed an ailing 68-year-old black veteran in his own apartment, a spokeswoman said Friday.
"Consistent with our office's practices in cases of this kind, we will review all of the available evidence with respect to the death of Kenneth Chamberlain, including the evidence collected during the state's investigation, to determine whether there were any violations of the federal criminal civil rights laws," said Ellen Davis, spokeswoman for the U.S. Attorney's Office for the Southern District of New York.
She spoke one day after a New York grand jury declined to indict Anthony Carelli, the officer who fired the fatal shots.
The officer's attorney, Andrew Quinn, released a written statement after news of the federal review broke.
"We remain confident that the Office of the United States Attorney will conduct a thorough, unbiased and complete investigation and will undoubtedly reach the same conclusion as the Westchester County Grand Jury: that Officer Carelli's actions, while tragic in result, were necessary to save the life of his fellow officer," he said.
The shooting occurred in November after police responded to a call that Chamberlain, who suffered from respiratory and heart problems, had set off his medical alert device, indicating he needed help. The encounter was recorded by audio and video devices that police released to the public to counter charges they had engaged in excessive force and racial profiling.
Westchester County District Attorney Janet DiFiore called the shooting "a tragedy on many levels" but said the grand jury had not chosen to indict after hearing from 42 witnesses, including Carelli.
"There were civilian witnesses, there were police witnesses, there were expert witnesses,100 exhibits went before that jury. And in this case, most of this event was captured in audio and videotape," DiFiore said. "All of that information was before the people who made the determination in this case."
Following her announcement, the White Plains Police Department released much of this evidence, including portions of the audio and videotapes and 200 pages of documents.
In the very early hours of November 19, Chamberlain had accidentally set off a medical alert pendant he wore around his neck in case of emergency.
The company that monitors the device alerted the city, which dispatched an ambulance to the scene. Police arrived first and are seen entering on a hallway security camera.
An audio tape of a speakerphone inside Chamberlain's apartment records the dispatcher asking Chamberlain if he is okay. He repeatedly says he is fine and asks for police to go away.
"This is your health center, Full life aid. Mr. Chamberlain do you need help?" they ask him at one point.
"Yes, this is emergency, I have the White Plains Police Department knocking on my door and I did not call them and I am not sick," he replies. He is then heard asking the police to please go away.
In the written reports, Officer Stephen Demchuk describes Chamberlain as an irrational man who stuck an 8-inch butcher knife through a crack in the door and jammed it shut with a chair when police tried to enter. Police carried a Taser gun with a video camera on it that recorded about 20 minutes of their efforts to get inside. A metal object is protruding through a crack in the door, but it is unclear what it is.
Next, police can be seen forcing the door open and firing the Taser at Chamberlain, who is wearing only shorts. He is standing there with only one arm visible at his side and yells "shoot me, shoot me, mother (expletive), shoot me:" It is unclear whether the Taser fire strikes him. He is left standing there when the video cuts off.
Police say that after the Taser failed they shot bean bags at Chamberlain, then forced their way in. Demchuk says Chamberlain made "continuous slashing motions towards my head and face" and that officer Carelli fired real bullets only when Chamberlain went after another officer "with the butcher knife raised."
Photos of the crime scene show signs of forced entry, blood on the floor and an overturned chair. There is no video of the shooting.
"He feared for his life," said Chamberlain's son, also named Kenneth. "He kept asking them to go away and that he didn't need their help." He said his father was an old man who was sick and said police were not justified in forcing their way in when he had committed no crime.
Chamberlain's niece, Tonya Greenhill, was outside the door with police, asking them to let her talk to her uncle instead of forcing their way in, she said.
"I heard my uncle begging and pleading them to please leave him alone," Greenhill said. "I could begin to almost hear fear in his voice."
Chamberlain, a former Marine, had such severe respiratory problems he could not walk a flight of stairs, according to his medical records. An autopsy released yesterday showed he had a blood alcohol level of 0.11 -- high enough to be considered legally drunk.
Greenhill, who lives in the building, said her uncle told them he was fine when they arrived but did not want to open the door. She said she insisted to police that they let him talk to his family, but they refused.
David Chong, White Plains public safety commissioner, told reporters: "We are obligated as a police department never to walk away from an emergency and we're not going to."
He added that his department would be reviewing the entire case and how they deal with emotionally disturbed people in the future. The city has said it will also conduct an independent review.
In wake of the case of Trayvon Martin, the unarmed, black 17-year-old who was shot and killed in Sanford, Florida, by a neighborhood watch volunteer, the Chamberlain case gained national attention with more than 206,000 signing an online petition asking for the district attorney to charge the officers involved in the shooting with murder and civil rights violations.
The family said they believed Chamberlain was treated differently because he lives in a housing project and is black. They said could hear one of the police officers on the audio tape referring to Chamberlain by using the N-word.
That was not part of the evidence released, but the district attorney confirmed it was on the tape and said: "The use of a racial epithet in any context is offensive to the dignity of all of us."