The lieutenant gives 50 to 60 presentations a year to authors, high school students, local historical societies, gun collectors and others interested in the historical significance of the guns and their connection to Berrien County.
Last week in Chicago, Kline showcased the Tommy guns during a convention of the Association of Firearm and Tool Mark Examiners.
Kline said the National Geographic cable channel will air a documentary featuring the weapons in a September documentary.
The guns also appeared on a 2009 episode of "History Detectives," a PBS show.
"There’s still huge interest in these things," he said.
Kline said the weapons, made in 1921, are fully functional and fired occasionally for maintenance.
He estimated their value at about $1 million each.
"A lot of them aren’t around anymore," Kline said.
What led Berrien County officers to the Tommy guns?
On the way to picking up his wife at the train station, "Killer" Burke was involved in a fender bender in St. Joseph in December 1929, Kline said.
The hit man, known as Fred Dane locally, fled from the wreck until a St. Joseph police officer, Charles Skelly, pulled him over.
According to Kline, Burke then fired three gunshots to Skelly’s chest. The officer later died.
Burke abandoned his vehicle, but inside the car, officers found a receipt listing Burke’s alias and address.
Kline said they went to Burke’s house and uncovered an arsenal containing the Tommy guns, grenades, thousands of rounds of ammunition, tear gas and other weapons. The officers also found about $325,000 from a Wisconsin bank.
Kline said Burke was arrested in Missouri more than a year later.
The Capone hit man was then convicted in St. Joseph and died in prison, Kline said.
The incident is inspiration for Kline’s niece, Chriss Lyon, a historian at the Berrien County Sheriff’s Department.
She said she was initially writing about Skelly’s death but now plans to detail background stories, including ones on the gangster population in Berrien County.
"The scope of it keeps getting bigger," Lyon said.
She said locals should take interest in the incident that led officers to the Tommy guns and an investigation that "put ballistics and forensics on the map."
"This is part of our history," Lyon said. "This is a Midwestern event, and we should be proud of it."
Staff writer Katlyn Smith: