On Nov. 15, a half century will have passed since Kennett Square Borough police officers Richard Posey and William Davis were shot down in the parking lot of the police station as they returned from night rounds.

Next Tuesday night, borough officials will mark those 50 years since the killings with a 6 p.m. ceremony in the 100 block of East Linden Street, where the shootings happened.

The public is invited to attend the ceremony and afterwards to meet with author Bruce Mowday, who recently released his book “Small Town Cops in the Crosshairs,” detailing the events of that early morning tragedy.

Borough Mayor Matt Fetick said guests may park in the borough garage, accessing it off Union Street and onto Linden Street.

The Pennsylvania State Police will provide an honor guard, and a memorial plaque will be presented. There will be limited seating.

Fetick and Police Chief William Holdsworth are still in the process of planning the details, but the mayor said local elected officials and law enforcement members will speak.

If it rains, the ceremony will be held inside the American Legion Hall.

At 7 p.m., Mowday will present a lecture in the legion hall detailing the history and events that led to the killing and eventual conviction of sniper Ancell Hamm. He will also have copies of the book for sale, which he will sign.

For Mowday, a prolific writer and former Daily Local News editor, the book is more than a tribute to the lives of the two men.

He said, “The sacrifices of William Davis and Richard Posey need to be remembered. When Schiffer Publishing asked me to research and write the book, I readily agreed.

“In a sense, the murders of the two Kennett Square policemen marked the end of innocence in small town America.”

Mowday has previously written the very popular and eagerly received book “The Jailing of the Johnston Gang.” Members of that gang were committing crimes and murders locally in southern Chester County in the 1960s and 1970s.

For many people who are too young to remember or who have arrived as residents in the meantime, the severity of the events is either a brief paragraph in borough history or something they have not even heard about.

For those who were present as adults at the time and felt the shock to the community, however, the memories are vivid.

Barber shop proprietor Bob Burton said he remembers that cold, damp day in mid-November 1972. When he first arrived at work in the morning, he said not many people knew what had happened, but the word got around fast.

“In those days, everybody in town knew each other. There was anxiety in the town, knowing there was a murderer. But it wasn’t like they were all going to go hide under their porches,” Burton said.

Burton knew both officers, had cut their hair, and was called upon before their funerals to groom them.

On that fateful day in 1972, Sandy Bertrando, who was then a young mother, was returning from an appointment later in the morning. She said she was puzzled because the town was surrounded by police cars, and she couldn’t get in.

“I called my father [“Sam” of Sam’s Sub Shop] and he told me what had happened. … I sensed there was a stunned silence in the town,” she said

Bill Taylor, of Taylor Oil, then an ascendant young businessman, was living on Marshall Street at the time. He said he was in bed and heard the gunshots. His wife was awakened by the noise as well, and told him she thought a truck had backfired.

Taylor said, “I told her that was no backfire. I’m a hunter and I know what a rifle shot sounds like. All those folks on Linden Street heard it, too, and the police interviewed them all.”

Hamm, the suspect, was found guilty after a lengthy trial and remains in prison. In a letter to Mowday, he maintains his innocence to this day.