HANOVER — A police officer killed while investigating a car crash was remembered by his brother-in-law as a family man, a fervent New England Patriots fan and a hero.

Weymouth police Sgt. Michael Chesna was laid to rest during a funeral Mass at St. Mary of the Sacred Heart in Hanover, where he lived with his wife and two children. A private burial service followed.

"Mike, you're my hero, and I'm truly honored to have known you personally and professionally," said Joseph Comperchio, Chesna's brother-in-law and a captain with the Weymouth police. "We love you, and we will miss you."

While friends, relatives, fellow Weymouth officers and political dignitaries packed the church, thousands of officers from departments across the country stood at attention outside.

Comperchio also read a letter from Chesna's wife, Cynthia Chesna.

"I would like to tell you that I love you more than anything in this world and that you are my best friend and best dad the kids could ever have," her letter said. "I will make sure the kids know how great you are and how fortunate I was to have you in my life."

Comperchio offered words of comfort to Chesna's wife and children, Olivia, 9, and Jack, 4.

"The members of the Weymouth Police Department are your family, and you will never be alone," he said.

Chesna, 42, was a native of Weymouth, a city of about 55,000 residents south of Boston. He was a U.S. Army veteran and Purple Heart recipient who had served tours of duty in Iraq and Afghanistan. He joined the Army after the Sept. 11 terrorist attacks and knew it would help him fulfill his childhood dream of becoming a policeman.

He played in a weekly men's basketball league and loved all Boston area sports teams, particularly the Patriots.

Chesna was killed last Sunday morning near the end of his overnight shift while investigating reports of an erratic driver and a car crash.

The man suspected of killing him, Emmanuel Lopes, threw a large rock at the officer, grabbed his gun and repeatedly shot him with it, police said. Lopes also is charged with killing a 77-year-old bystander, Vera Adams.

Lopes, 20, has pleaded not guilty to two counts of murder.