Dozens gathered Sunday afternoon for a vigil in front of the White Plains Department of Public Safety to mark six years since a man was killed by White Plains police after officials said he threatened an officer.

Community leaders, religious leaders and concerned citizens joined together to remember Kenneth Chamberlain Sr.

The 68-year-old African-American man was fatally shot in his home at the Winbrook Public Housing Complex in November of 2011.

Chamberlain's family says that on that day, he had inadvertently triggered his medical alert device, causing officers to respond. The family says Chamberlain -- a former Marine and veteran of the Westchester County Department of Corrections -- didn't want to let officers inside, assuring them everything was OK.

The family says officers broke in, used a Taser on Chamberlain and then fatally shot him.

The police officer involved in the shooting, Anthony Carelli, reportedly claimed that Chamberlain lunged at another officer with a knife, prompting him to pull the trigger.

Carelli was cleared of any criminal wrongdoing in 2012. Last year, a civil lawsuit against the city and its police department was rejected.

Chamberlain's family says they can't bring their father back but hope change can be made.

"'Justice for Kenneth Chamberlain Sr.' is about now changing policy, changing laws, breaking down the structure of racism within the institutions and things of that nature. But we do that by working together," says Chamberlain's son, Kenneth Chamberlain Jr.

Chamberlain's family says they have filed an appeal and are seeking another trial.

News 12 reached out to the White Plains public safety commissioner for a statement and is awaiting a response.