MANCHESTER, N.H. (AP) – The man charged with fatally shooting and killing a police officer in October pleaded not guilty at his arraignment on a charge of capital murder Tuesday.

Michael Addison, 26, of Manchester, was charged with shooting Officer Michael Briggs on Oct. 16. He won’t be granted bail because of the seriousness of the charge, court officials said.

The plea sets in motion a lengthy period of complicated litigation that could ultimately end in Addison’s execution. Addison was the first person charged with capital murder in the state in a decade, and if convicted could be the first to be put to death in about 70 years.

“Certainly in a capital murder case, it will be a difficult and complex case, but this is the beginning of the case,” Attorney General Kelly Ayotte said. “We expect the defense will file motions before trial. We’ll fight any of those motions. We don’t know what they’ll be.”

Prosecutors said Addison shot the 35-year-old father of two in the head as police attempted to question him about a domestic incident.

The courtroom was packed with uniformed officers along with Briggs’ mother and other family members.

“My office will pursue this case vigorously and professionally as we move this case to trial,” Ayotte said.

A scheduling conference to determine a trial date is expected to be held next week.

Briggs’ death sparked an outpouring of grief in Manchester and a bill at the Statehouse. If passed, “Michael’s Law” would add a $100,000 state payout to the benefits provided to the families of police officers and firefighters killed in the line of duty.