SANFORD, Maine — Maine State Police are investigating the shooting death of a well-known Maine political opinion writer at his home Wednesday evening.

Police said Michael Harmon, 71, died at his house on Brunelle Avenue when he was showing a teenage boy a handgun and the gun went off.

Harmon’s daughter confirmed by phone Thursday morning that her father died Wednesday night.

The 16-year-old was handling the gun at the time, according to police.

An autopsy is scheduled at the state medical examiner’s office, and the case will be reviewed by the attorney general’s office.

The teenager and his father, both from North Berwick, were at the home at the time.

Detectives said everyone has been cooperating.

Harmon was employed by the Portland Press Herald for more than 41 years, beginning in 1970 as a reporter and later as an editorial writer and most recently a columnist. During his four decades, Harmon gained a reputation as one of Maine’s most strident conservative voices.

Former Portland Press Herald editorial page editor John Porter said Thursday he started with Harmon as an editorial writer and later became his editor.

“Although Mike and I came from different parts of the political spectrum, we actually found a lot of common ground over the years,” Porter said. “Mike liked to run up the volume on his column, as a conservative writer, but he was also very compassionate and could be a very pragmatic person as well. He always came from the right place in terms of his motives.”

Harmon graduated from Bowdoin College, and served for 25 years in the U.S. Army Reserve, including two years of active duty in Vietnam. He retired as a lieutenant colonel.

Porter said Harmon was proud of his military service and “carried that part of his life with him always. When we would talk about issues, he would always talk about the importance of honoring veterans and making sure people understood how difficult it is for people to serve.”

Harmon retired from journalism in 2011, but he continued to work as a freelance writer and speaker. As news of his death became public Thursday morning, messages of condolence to his family and colleagues at Maine Today Media poured in from throughout the state.

According to the Portland Press Herald, Harmon is survived by his wife, three children, two stepchildren and several grandchildren.

Portland television station WGME, CBS 13, contributed to this report.