Mistrial for man charged with killing a Weymouth police officer and a bystander

The trial of a Massachusetts man charged with killing a police officer and an innocent bystander while fleeing a car crash was declared a mistrial on Monday because the jury couldn't reach a unanimous verdict.

Emanuel Lopes, 25, pleaded not guilty to 11 charges, including two counts of murder, in connection with the killings in July 2018. Prosecutors say he shot Weymouth police Sgt. Michael Chesna, 42, a military veteran and married father of two, as well as bystander Vera Adams, a 77-year-old widow.

Chesna’s widow sobbed when the mistrial was announced by Norfolk Superior Court Judge Beverly Cannone after a monthlong trial including about two weeks of jury deliberations.

Prosecutor Greg Connor said Lopes was a calculating killer, but the defense said in court that he lacked criminal responsibility because he had a long history of mental illness and was in “a state of oblivion” on the day of the killings.

Chesna's family declined comment when they left the courthouse.

Outside, Weymouth police Chief Richard Fuller said the department is “extremely disappointed," with the mistrial but insisted that "We will have justice.”

The Norfolk district attorney’s office says it will retry the case.

Lopes was fleeing the scene of a minor car crash and Chesna was investigating. Prosecutors say Lopes threw a large rock at the officer’s head, knocking him to the ground unconscious, then grabbed the officer’s gun and shot him multiple times.

As he fled, Lopes shot Adams, who was on her porch. When he was caught, Chesna’s service weapon was out of ammunition, authorities said.