Barnstable, MA – Yarmouth Police Officer Sean Gannon was fatally shot while serving a warrant on Thursday.

Police said that Officer Gannon and his K9 partner Nero were trying to serve a warrant at a home on Blueberry Lane in the Marstons Mills section of Barnstable at about 3:30 pm on April 12.

Time reported that they were searching for the suspect in the attic of the house when he opened fire on them.

Officer Gannon, 32, was fatally shot in the head. The Massachusetts State Police (MSP) said that Officer Gannon’s K9 partner was also seriously injured, the Boston Herald reported.

The suspect barricaded himself inside the residence immediately after he shot Officer Gannon, and then a gunfight ensued with police, Time reported. A black, armored tactical vehicle was used to gain entry to the home, and take the suspect into custody.

Officer Gannon was transported by ambulance to Cape Cod Hospital in Hyannis where he died.

K9 Nero was taken for emergency veterinary care. His condition was unknown, Time reported.

The Cape and Islands District Attorney’s office identified the shooter as 29-year-old Thomas Latanowich of Somerville, a career criminal with at least 111 charges already on his record, the Somerville Patch reported.

Yarmouth Police Lieutenant Steven Xiarhos called him a “notorious and violent criminal” when he was arrested for stabbing a man who had just gotten out of prison in December of 2017.

Assistant District Attorney Tara L. Miltmore said in a statement that Latanowich will be charged with murder when he is arraigned Friday at First District Court in Barnstable.

Massachusetts Governor Charlie Baker extended his condolences on Thursday night.

“I am heartbroken to learn of the passing of Officer Gannon and my thoughts and prayers are with his family, loved ones and the Yarmouth Police Department after this tragic loss,” Baker said in a statement, according to the Boston Globe.

“The Commonwealth is blessed to have courageous men and women who put their lives on the line to protect our communities every day,” the governor wrote.

As news of Officer Gannon’s murder spread, police departments and supporters took to social media to express their condolences and celebrate the life of the fallen hero.

“With deep sorrow and heavy hearts the Yarmouth Police Department reports the loss of Officer Sean Gannon. Officer Sean Gannon was killed in the line of duty today,” the Yarmouth Police Department posted on their Facebook page.

MSP tweeted its condolences along with wishes for Officer Gannon’s K9 partner’s recovery.

Officer Gannon joined the Yarmouth Police Department (YPD) in December of 2010, and became the department’s first full-time K9 handler one year later, WCVB reported.

He had previously served on the Stonehill College Police Department and the Nantucket Police Department, according to the Officer Down Memorial Page.

Officer Gannon’s wresting partner attended the procession that took his fallen’s friend’s body from the hospital, and held up American flags with his young daughter as the officer’s body passed by them, the Boston Globe reported.

“I’m really glad to see so many officers supporting my friend,” Robert Horne said. “I felt that it was important that I bring my daughter out here so she could see how important his life was. To me and so many other people.”

Our thoughts and prayers are with the family of Yarmouth Police Officer Sean Gannon, both blood and blue. Thank you for your service.

Officer Sean Gannon, your life mattered.