On Thursday, Toronto’s longest serving homicide detective closed the book on a career that has spanned nearly four decades.

Detective Sergeant Gary Giroux has worked on about 200 homicide cases during his 40 years with the Toronto Police Service

“I've had some good successes over the years and like everybody in the office I've had some disappointments and I’ve had to remind officers within our unit, the younger ones, that those disappointments are just part of this particular process.”

Giroux started his policing career in 1979 as a self-described “straight laced” 19-year-old. He told CTV News Toronto that he always knew he wanted to be an officer, something he says gave him comfort during his youth.

“It was really always something I had in my mind,” he said. “It was that kind of a community contribution I wanted to make.”

He said one of the things he enjoyed about his time with the police service was the variety of work he was exposed to.

“It was exactly what I expected it (to be) and had hoped for and quite frankly I had made comments to my wife that when I was a young constable, the days off were really an inconvenience because I was ready to get back to work.”

Giroux moved to the homicide unit in the mid-90s after being invited to apply. He said that of all the cases he has worked on, he is most proud of putting serial sex offender Stuart Cameron behind bars.

In 2000, Cameron attacked two Taiwanese sisters who had come to Toronto to study English. One of the women was killed. DNA linked Cameron to other sexual assaults in the area.

While working the case, Giroux told reporters that while he may not be a police officer in 20 years’ time, he will be “available to the parole officer to tell them exactly what kind of monster Cameron is.”

And he is keeping that promise. Giroux said that he reached out to the parole officer last week because he had “some concerns” about Cameron’s release.

Giroux told CTV News Toronto that he credits his wife for his success with the Toronto Police Service.

“I can't tell you the number of times that I've said to her ‘I got to go’ as a result of phone calls in the middle of the night, or middle of the day or anniversaries, or birthday parties for the kids,” he said. “She knew it made me happy.”

All of that is about to change as Giroux turns in his firearm and becomes a private citizen. He said he is looking forward to his daughter’s wedding and an eventual move somewhere rural.

“It's a strange feeling, I've had one employer for 40 years unlike most people in the private sector … I’ve never been exposed to anything else in my adult life,” he said. “I’ve indicated to my family that I’m just going to lean into it.”

With files from CTV News Toronto's Michelle Dube