Thomas Latanowich Guilty Of Second-Degree Murder For Killing Yarmouth Police Sgt. Sean Gannon

BARNSTABLE (CBS) - Thomas Latanowich was found guilty of second-degree murder Friday for shooting and killing Yarmouth Police Sgt. Sean Gannon in 2018.

The jury in Barnstable Superior Court found Latanowich guilty on all seven charges against him, including aggravated assault with a dangerous weapon, assault and battery with a dangerous weapon, using a firearm in commission of a felony, possession of a firearm without an FID card, possession of ammunition without an FID card and mistreating a police dog.

Latanowich was sentenced to life in prison with the possibility of parole in 25 years for the murder charge, plus 10-to-15 years on other charges.

Gannon's family was hoping for a first-degree murder conviction which would have meant life in prison without parole for Latanowich.

Gannon's wife Dara read a victim impact statement after the verdicts were announced but before sentencing.

"I have recurring nightmares and I cry myself to sleep often," she told the court. "When the worst thing you can imagine comes true it shakes your whole world view."

Watch: Dara Gannon Statement

"I'm constantly worrying and waiting for the next terrible thing to happen," she said. "Grieving publicly is very difficult. Sean and I were both private people. It's unusual to become a widow at 31, and even more so by murder. People don't know what to say to me. Sometimes I feel like a pariah."

She called her husband the "most beautiful soul I ever met."

"Sean's life and my future with him were taken away. Taken by a heinous act of violence from a career criminal that was allowed to remain on the streets," she said.

Gannon was shot and killed while he and other officers were serving an arrest warrant at a home in Marstons Mills on April 12, 2018. Gannon's K-9 partner Nero was also shot, but survived. Latanowich was wanted for violating his probation and was holed up in the attic of the house when investigators say he shot Gannon and Nero.

Latanowich took the stand in his own defense Monday, saying said he was hiding in the attic because he was afraid after someone had tried to kill him just weeks earlier. Latanowhich claimed he didn't know it was police entering the attic when he shot Gannon once in the head, killing him.

During closing arguments Tuesday, prosecutor Michael Trudeau said the shooting was not a case of self-defense. He pointed to text messages and voicemails that Latanowich sent just 10 minutes after he shot Gannon, saying, "I'm taking as many as I can," allegedly referring to police officers.

Trudeau claimed Latanowich had spent the last 40 months concocting the self-defense story.

Jurors deliberated for more than three days after getting the case Tuesday.

Gannon's mother, Dennis Gannon, spoke in court on Friday.

"No one would wish this crushing, suffering death of one's child on anyone," she said.

His father, Patrick Gannon, also spoke in court Friday, describing the loss of his eldest son.

"I'm forever since the moment Sean was brutally and unjustly taken from us," Patrick Gannon said.

Gannon's family released this statement Friday:

Our family would like to express our sincere thanks to the District Attorney's team that prosecuted this case and to all of the Court staff that provided support and kindness, and who assisted us throughout this very difficult process. In addition, we are profoundly grateful to the Yarmouth, Barnstable and Massachusetts State Police Departments, and all law enforcement members who have exceeded our expectations in the way of care and compassion to our family.

While we are disappointed in the verdict, the fact remains that our Sean is dead.

We are completely grateful and extend our heartfelt thanks to the many members of our communities that have reached out to our family in myriad ways throughout these past three years. Their support has been the steel in our spine: you will never be forgotten.

Now, we must continue to honor Sean's legacy of service. We will do so through the Sean M. Gannon Memorial Fund as we attempt to make our world a better and safer place. Our family will make no further statements. We need time to quietly reflect and heal.

Any further inquiries may be directed to our family counsel, Bruce A. Bierhans, or to the Sean M. Gannon Memorial Fund through the Cape Cod Foundation.

Thank you very much.

The Family of Sergeant Sean McNamee Gannon