Kenneth Chamberlain, Sr., a veteran of the Marines, was fatally shot on November 19, 2011 by White Plains, New York police officers who claimed the retired corrections officer was a lethal threat. Chamberlain was 68 years old.

The police had been dispatched to his apartment in the Winbrook Houses public housing project because Chamberlain had accidentally tripped off his medical alert pendant. Despite warning officers about his critical heart condition when they arrived, they knocked down Chamberlain’s door, tasered him, and shot him with a beanbag gun in what they stated later was an attempt to subdue him.

Eventually, the conflict escalated until an officer shot Chamberlain in the chest at the climax of an early morning standoff that lasted nearly an hour.

Kenneth Chamberlain, Sr. died of his wounds two hours later at White Plains Hospital. Now his son, Kenneth Chamberlain, Jr., is pressing for the arrest of the officers involved in his death.

When his father was killed, the family was promised that a full investigation would be conducted. The White Plains police commissioner soon concluded that Chamberlain was emotionally disturbed and dangerous at the time of the shooting, justifying the force used. Yet, eye witness reports of the final hour of the veteran’s life were far more complicated than the portrait painted by police.

The case of Trayvon Martin spurred Chamberlain’s family to push for more answers, and is cited as a major reason for renewed interest in the former Marine’s death. Unrest regarding the Feb. 26 killing of the unarmed black teen in Sanford, Fla. by a neighborhood watch volunteer has spurred media interest in similar cases leading to numerous articles detailing the unanswered questions regarding Chamberlain’s demise.

Pieces have appeared in the New York Times, the Daily News, and on the Huffington Post among other outlets.

An online petition called “Justice for Kenneth Chamberlain Sr.,” which was started by his son, has garnered almost 199,900 signatures. It states, “We, the undersigned, implore Westchester County District Attorney Janet DiFiore to no longer allow police misconduct, brutality, or criminality to happen in this community and ask that these officers be indicted and charged with murder and civil rights violations.”

Combined with the persistent protests of Chamberlain’s family and growing attention, due to the charged context of the Martin tragedy, the Westchester County DA has scheduled a grand jury investigation into the cause of Kenneth Chamberlain, Sr.’s death that will convene within days.

After five months with little attention, the troubling events surrounding the day Kenneth Chamberlain, Sr. died will soon receive intense legal scrutiny.

A medical emergency response becomes a lethal standoff

When police were sent to Chamberlain’s apartment — a typical protocol if a patient does not respond to operators after a medical monitoring system is triggered — they claim Chamberlain was violent, emotional, and wielding a knife. They had been dispatched to check on Chamberlain’s well-being, but stated in their official report that noises from within the apartment raised concerns that someone inside was being harmed.

The White Plains officers then began to forcibly enter the unit.

Chamberlain’s medical alert system included a two-way communication device that remained connected with the operator who had dispatched the police. The entire incident was recorded on this device, in addition to a camera housed on a police taser device, and a residential security camera.

Chamberlain can be heard on the audio recording saying that he does not need their help, and requesting that the police leave.

The police claim that it was necessary to have the door opened completely to ascertain whether Chamberlain was safe. When the resident refused, officers stated that removing the door from its hinges was necessary for thorough confirmation.

At this point, it has been reported that one of the videos shows a metal object slipping into the hallway from within the apartment, which police suspected was a weapon. Soon after, the fire department arrived, and fireman began to take the door off its hinges.

When the door is off, the video shows Chamberlain standing calmly with his arms at his sides and his hands empty.

In the course of these events, Chamberlain’s niece, Tonyia Greenhill, who lives on a floor above him, came down to intervene. The LifeAid medical alert worker who sent the emergency support also offered to call Chamberlain’s family to quell the crisis in response to the commotion, and tried to recall the request for police help. Both attempts to mitigate the situation were dismissed by officers, according to recordings and witnesses.

One officer was also heard saying, ”’I don’t give a f**k ni**er, open the door,” in response to Chamberlain’s repeated pleas for the police to disband. Another is heard stating, “I need to use your bathroom to pee!”

Chamberlain reportedly said, “Why do you have your guns out? …You’re going to come in here and kill me.”

Another person said, “Turn it off,” presumably about the video camera on the taser, before the video ends.

These details have been related to various sources by Chamberlain’s son and lawyers who screened the tapes in February.

The grand jury and an officer’s tainted history

The audio and video recorded during this altercation will be reviewed during the grand jury investigation. Currently, Chamberlain’s family, lawyers, and law enforcement officials are the only people who have reviewed this evidence, which authorities have stated will not be released to the public.

Former Westchester County prosecutor Mayo Bartlett, one of the Chamberlain family attorneys, was highly disturbed by what he witnessed. “I could not sleep after that,” he told ABC News New York about the tapes, “And it was absolutely mind-boggling that a person given these circumstances who at best called for medical assistance, at worst mistakenly hit a button that triggered a medical alert system to go off, would be held almost essentially at bay in his apartment.”

Bartlett has also said police did not give Chamberlain a chance to demonstrate acquiescence.

“The minute they got in the house, they didn’t even give him one command,” Bartlett said. “They never mentioned ‘put your hands up.’ They never told him to lay down on the bed. The first thing they did…you could see the Taser light up… and you could see it going directly toward him.”

The shooting was not recorded, but news reports have revealed the name of the shooter.

The Daily News uncovered that officer Anthony Carelli shot and killed Chamberlain on November 19, and is a current plaintiff in a federal police brutality case due to be heard this month. Carelli and five other officers in that case stand accused by twin brothers Jereis and Salameh Hatter of brutally beating them in 2008 and calling them “rag heads.”

The Hatter brothers, who are of Jordanian decent, are suing the officers in a civil suit for $10 million.

White Plains city officials have confirmed that Anthony Carelli was the officer that killed Kenneth Chamberlain, Sr. following the leak. Westchester County officials had been attempting to keep Carelli’s name a secret. The police department has stated that Carelli was placed on administrative duty after the shooting.

The president of the White Plains Police Benevolent Association offered a statement in support of Carelli on Thursday. “We are very disappointed that anybody would release the name of this officer during an ongoing investigation,” President Rob Riley said. “Officer Anthony Carelli has numerous commendations and has been an excellent police officer, both on and off the job, and he deserves the right to a fair and impartial inquiry.”

White Plains Mayor Tom Roach has extended his condolences to the Chamberlain family, but otherwise has not commented on the case.

Kenneth Chamberlain, Jr. hopes that the police involved will be charged and that the White Plains police department will be sanctioned for its incomplete investigation into his father’s death as a result of the grand jury’s probe.

Ultimately, he hopes his father’s killing will be recognized as a hate crime.

“I try not to say something is racial, and I never said this was racially motivated,” Chamberlain said. “But in my opinion anytime you use the N-word and there is injury or death, I look at it as a hate crime.”

Follow Alexis Garrett Stodghill on Twitter at @lexisb