An unarmed, mentally ill African-American man died in police custody in upstate New York, after being tasered by officers. Albany authorities promised a full investigation, while activists have announced a protest.

READ MORE:Taser used by officers blamed for setting man ablaze—and not for the first time, either

The family of Donald “Dontay” Ivy, 39, described him as a paranoid schizophrenic who suffered from heart problems, but kept to himself and was not violent by nature.

According to the police, three officers approached Ivy at 12:30 at night on Thursday, citing “suspicious activity.” Ivy allegedly became aggressive, and ran away from the officers, who tasered and tackled him to the ground. They said he continued to struggle after being handcuffed. After Ivy lost consciousness, the officers say they tried to revive him, but without success.

RT @ShaunKing: Donald Ivy. unarmed. Suffered from severe schizophrenia. Was just killed by police in Albany, NY. pic.twitter.com/vnUyen70cc — jamalbryant (@jamalhbryant) April 3, 2015

“I'm still trying to figure out how it escalated,” Ivy’s first cousin Celestal Hightower told the Albany Times-Union. “The whole thing just doesn't make sense. I don't know what they did. I don't know how it came about. I just want it to make sense.”

“We're going to do a thorough investigation and we're going to get all the answers,” said acting Police Chief Brendan Cox on Friday. He told reporters that Ivy had been unarmed, but that the autopsy and toxicology results were still pending.

Citizens rally in protest of the death of Donald Ivy after he struggled and was tazed by Albany Police. #donaldivypic.twitter.com/hESoakaCfv — Cindy Schultz (@cschultzphoto) April 3, 2015

Cox took over the department last Friday, after the retirement of Chief Steven Krokoff. The three officers, identified as Michael Mahany, Joshua Sears and Charles Skinkle, have been placed on leave until the investigation is concluded.

“I ask that everyone respect the process and await the results of the investigation,” Albany mayor Kathy Sheehan said. “Our condolences go out to the family during this difficult time.”

Community activists have called for a protest on Friday night outside the city police department’s South Station, but Ivy’s family said they would not be involved.

At the Albany Police South Station where a protest is expected at 7pm following death of Donald Ivy. pic.twitter.com/esfAZdninm — Brandon Lewis (@CBS6Brandon) April 3, 2015

“There's a lot of missing information right now,” said Hightower. “We just want to wait until everything is presented to us and then maybe there will be satisfaction, maybe not. We don't know until it is all presented. So that's what we're waiting for.”

READ MORE:Tasers have killed at least 500 Americans

Considered a “non-lethal” weapon, a Taser can discharge upwards of 50,000 volts. The devices were described as “a form of torture” provoking “extreme pain” by a 2007 statement by the UN Committee Against Torture. A February 2012 report by Amnesty International said over 500 Americans had been killed by Tasers since 2001. By late 2014, that number has risen to 634, according to the blog Electronic Village.