Attorney General Janet Mills said she’s concerned with the dramatic rise in the number of people shot to death by Maine law enforcement officers this year but is satisfied with the standards her office uses in deciding whether fatal force was “justified.”

Twice as many people have been fatally shot by Maine police so far this year as in all of 2016 and 2015 combined. The attorney general’s office since 1990 has been in charge of investigating such cases and has never found a shooting unjustified.

“The number of fatal police shootings this year is concerning,” Mills said. “The standard applied to police in the use of lethal force is the same standard applied to civilians under the law so they can protect themselves and/or others from the threat or use of deadly force.”

Between Jan. 1 and June 7, 2017, eight people were killed by officers from seven different agencies.

In 2016, Maine police killed just two people, the same number as in 2015. Likewise, the death toll in 2009 and 2012 was two.

The eighth fatality of 2017 was Mark Ellis, 54, of Orrington. He was shot and killed by Maine State Police more than 12 hours after Penobscot County deputies arrived at Ellis’ home.

The Maine attorney general’s office was tasked by the Legislature in 1990 with determining whether an officer’s use of force was justified under state law. Before that, law enforcement agencies had the option of opening an internal investigation or asking the attorney general’s office to conduct its own. Neither Mills’ office nor legislators have sought to change how investigations are handled, the attorney general said.

But the ACLU of Maine said more needs to be done to prevent police shootings, though it has not called for changes in the way the use of deadly force is investigated.

“The death of another person at the hands of a police officer should always be an absolute last resort, not something that happens on a monthly basis,” Zachary Heiden, an attorney with the organization said. “With shootings by police on the rise in Maine, we need to go beyond asking ourselves whether a shooting was legally justified in the technical sense of the term and start asking whether it could have been prevented.”

So far, the Legislature has limited the attorney general’s review to whether criminal charges are warranted.

“Questions about ‘what an officer might have done differently’ can be addressed in civil actions, personnel actions or through the incident review team process,” Mills said.

Anecdotal evidence shows that much more often than not police defuse a situation such as the one in Orrington without firing shots, though the attorney general’s office does not formally gather data, Mills said.

“We don’t track them, but we should,” she said. “Often these situations are in conjunction with a domestic violence call. And no one can predict what will happen when a person is waving a gun around and threatening people.”

Why has every shooting investigated by the attorney general’s office been ruled “justified”? Part of the reason might be that investigators most likely start from the premise that police shootings tend to be justified, the way police interviewing a suspect often start from the premise that the person is guilty, Philip Stinson, associate professor in the Criminal Justice Program at Bowling Green State University in Ohio, speculated.

The central test in the Maine investigations is whether — in the heat of the moment — the police officer thought the person who was shot was otherwise going to kill or hurt the officer or someone else. The review hangs in part on the standard of reasonableness, a legal test pervasive in the American justice system that is based on what investigators believe a reasonable person would do.

Over the years, the length of time investigators have taken to complete their reports has grown dramatically. In 1997, an investigation determined in less than a week that a Bangor police officer’s shooting of a 27-year-old man outside his Broadway apartment was justified.

Recent investigations have taken from three to 18 months. The last report — on a May 2016 shooting by a Presque Isle office — was issued on Dec. 19.

“We try to work through them as quickly as possible,” Mills said. “While we are sensitive to the public interest in having a quick resolution, our responsibility is to conduct a thorough investigation.”

She added,“It can take months to process, catalogue and review all of the physical and electronic evidence collected at a scene, review medical records, if they exist, conduct interviews with any witnesses, conduct any necessary follow-up interviews and then to make a determination based upon the totality of the evidence.”

Maine is unique in assigning investigation of all fatal shootings by law enforcement officers to the attorney general’s office, according to Urey Patrick, coauthor of “In Defense of Self and Others … Issues, Facts, and Fallacies: The Realities of Law Enforcement’s Use of Deadly Force.”

“I am not aware of any other state that has that,” Patrick, formerly of Winterport, said. “[Elsewhere] large departments handle their own investigations with consultation from whatever prosecutorial system they have. Smaller departments without the resources to do their own investigations will ask the state police of the attorney general’s office to investigate to maintain the required objectivity.”

Longtime legislator Sen. Bill Diamond, D-Windham, who is a member of the Criminal Justice and Public Safety Committee, and Robert Schwartz, director of the Maine Chiefs of Police Association, said they are satisfied with how the attorney general’s office investigates officers’ use of deadly force.

“A majority of officers in Maine never use their firearms in the line of duty,” Schwartz said. “These incidents are rare. If you had a way to measure the times that police police officers defuse situations that could have been fatal, you’d see how rare they are but [defused incidents] go unreported [by the media].”