New statement from authorities details moments before shooting of Yarmouth officer

K-9 Officer Sean Gannon was killed in the line of duty on April 12.

Yarmouth Police Sgt. Sean Gannon.
Yarmouth Police Sgt. Sean Gannon was killed in the line of duty April 12, 2018. –Yarmouth Police

Prosecutors released new details on Thursday about the fatal shooting in April of Yarmouth Police Sgt. Sean Gannon.

Cape & Islands District Attorney Michael O’Keefe said in a statement that Gannon, 32, and his K-9 partner Nero were shot during a second sweep of the attic of a Marstons Mills home where his alleged killer was hiding with thousands of dollars of cash and a bag of drugs.

Gannon responded to the home on Blueberry Lane on April 12, joining six other officers from Barnstable, Yarmouth, and state police who were attempting to serve an arrest warrant for Thomas Latanowich for a probation violation out of Middlesex County.


After clearing the house, the DA’s office said Gannon and his K-9 entered the unfinished attic of the home through a hole in the ceiling of a small bedroom closet along with another officer. They found two backpacks  — one containing a “large amount of drugs” and the other filled with clothing — but left the attic after not finding anyone.

“Shortly thereafter, following further evidence that someone was in the attic, they once again went into the attic through the same hole in the closet ceiling,” prosecutors said.

This time, while sweeping through the attic, Gannon, Nero, and two other officers observed that a piece of insulation was covering an opening into another section of the attic that had been created by an addition to the home.

“Immediately upon removing the insulation Sgt. Gannon sustained a gunshot wound,” the DA’s office said.

The officers in the attic pulled the 32-year-old down through the hole in the closet ceiling and “began to attend to him.” The officers at the scene evacuated the home and created a perimeter around the building.

Gannon was pronounced dead at Cape Cod Hospital.

The DA’s office said “after a period of time” Latanowich, 29, surrendered to the authorities and was taken into custody. He has been charged murder in the first degree and one count of mistreating a dog.


After Latanowich was arrested, Gannon’s partner, Nero, was removed from the home suffering from a gunshot wound. He has since been released from the hospital and is recovering, according to Yarmouth police.

In the days after the shooting, investigators found a semi-automatic handgun broken into several pieces — slide, spring, magazine, barrel, and frame — hidden in different parts of the house and more than $25,000 concealed in a bedroom wall, according to the DA’s office. More than $4,000 was also discovered with Latanowich when he was booked.

The DA’s office said the case remains under investigation.


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