The well-respected officer joined the force as a 17-year-old police cadet at Redfern in 1962 before being officially sworn in on his 19th birthday.

But his connection with the NSW Police Force started well before that when he was born at Gulargambone Police Station in the central west plains in 1944.

His father, uncle and great-grandfather also served as police officers.

"I had a lifetime in the cops - it is in my blood," Sen Sgt Thompson said in a statement on Sunday.

Sen Sgt Thompson, 77, said the job has given him the opportunity to meet people from all walks of life, which has led him to experience the best and the worst of many individuals over the years.

"I've seen people at their highest and at their lowest. We used to put people from all walks of life in the back of the truck," he said.

Sen Sgt Thompson started as a probationary constable at Parramatta Police Station and has worked in various commands across the force, including Chatswood, Surry Hills, the police transport branch and the 21 Division, which was the training ground for the criminal investigations branch.

"I was at Parramatta in 1971 when a call came over about people causing trouble. By the time we got there, Sergeant Bill Riley and Sergeant Maurie McDiarmid were sadly shot dead in Toongabbie. That's something I'll never forget."

Sen Sgt Thompson received several police awards as well as a letter of thanks for his service from the Duke and Duchess of Cambridge following their visit to Australia in 2014.

He has worked in the state planning unit at major events across NSW for the past 20 years and his last arrest, for an alleged aggravated robbery, occurred three years ago while working at the New Year's Eve celebrations.

Sen Sgt Thompson began long service leave last Friday and will officially retire in January 2023 after 61 years with the force.

Australian Associated Press