TROY – Chief John Tedesco straps on leg braces every morning before he heads to police headquarters to supervise his 130-member force.

"If you're a police officer, you need to move — mobility is important," Tedesco said Friday, the day he announced that he'll retire next month.

It was also the day the 63-year-old went public with the fact that he has been fighting amyotrophic lateral sclerosis, better known as Lou Gehrig's Disease, for the past three years.

Tedesco will leave after 42 years as a Troy police employee. He has led the department since 2010, when he was promoted to chief by former Mayor Harry Tutunjian.

“It’s time for a new chief," Tedesco said. " ... I’ll miss it.”

ALS is a particularly cruel diagnosis. The progressive neurodegenerative disease affects nerve cells in the brain and the spinal cord, stripping away strength and motor control. No cure or treatment currently exists to stop or reverse it, though progress had been made in learning more about it.

Tedeso has worked to stay steady on his feet. He has had to deal with the loss of strength while urging his officers to be strong in performing their duties.

That has meant adapting over the past three years. It's also involved traveling to Boston to receive experimental treatments.

"I'm feeling strong," he said.

When Tedesco exits for the last time on Jan. 12, he plans to head to Florida to escape the cold. When he returns, he has a new mission lined up: Establishing a foundation called "Arrest ALS" that will raise funds to help purchase equipment for patients with the disease who lack financial resources.

Mayor Patrick Madden learned of the chief’s retirement decision Friday morning. Tedesco has spoken off and on over the past year about retiring, but always made it clear it would be hard to leave a job he would do all over again for another four-decade career.

“We’ll miss the experience and the historical knowledge he brings to the table every day,” Madden said.

The mayor said Tedesco is handling the disease well. "It’s a tough, very scary diagnosis. I wish him the best of success,” Madden said.

Tedesco is known for his passion for the job, said Councilman Mark McGrath. “He was a tough chief, by the book. He didn’t put up with a lot of nonsense,” McGrath said. “He ran the department the way he felt it should be run.”

Tedesco’s promotion to police chief on April 2010 came with a roar of gunfire.

The day his appointment was to be announced, Tedesco was out on the street responding to two back-to-back shootings. Later, he had to lead the department after two fatal shootings by police officers in 2015 and 2016 — traumas for the force as well as for the larger community.

“I was really proud of leading the department through that and keeping the officers focused,” Tedesco said.

The chief also dealt with the January 2014 brawl at Kokopellis, a now-shuttered Fourth Street bar and nightclub, in which officers responded to reports of a fight. Tedesco responded to claims of police brutality by defending his officers and working with the FBI to determine if the officers acted properly in the use of physical force. The FBI investigation found the officers responded properly.

The chief said he would like to have stayed on to see the completion of the grand jury investigation of the department’s drug unit, formally known as the Firearms Interdiction and Narcotics Suppression Unit. In that case, officers allegedly entered an Oakwood Avenue residence without a search warrant. After the term of the grand jury was extended, Tedesco said he decided not to wait for the result.

Tedesco often confronted the Troy Police Benevolent Association over matters involving overtime and other rules. He sought to end the strict seniority rules in the PBA and captains’ unions in order to have better control over assignments to specific units.

Tedesco pushed for cameras in police cars, and for officers to wear body cameras. This proposal, however, has become mired in city bureaucracy.

The chief said he was proud of “getting the department the different tools it needs and keeping up with the times.”

Madden said he will begin interviewing for Tedesco’s successor in the near future. He said he doesn’t want to leave the job vacant for too long. On the promotion list are Assistant Chief Brian Owens, Capt. Daniel DeWolf and Capt. Christopher Kehn. Madden recently interviewed them for the open assistant chief’s position, which Owens was appointed to fill. Madden said the three would be re-interviewed.

On the day he announced his retirement, Tedesco was working his police department’s future: interviewing candidates to fill the five police officer vacancies. The city anticipates announcing its appointment of new police officers in January.

"The thing with ALS — it's what you make of it," Tedesco said. "I'm not giving in."