Details surrounding the shooting death of U.S. Marine Corps veteran James Popkowski by public safety officers and a decision on whether the shooting was justified will not be finalized for weeks.

If history is any indication, though, the shooting will be ruled just.

Popkowski’s death Thursday morning outside the Veterans Affairs Medical Center at Togus is under investigation by the Maine Attorney General’s Office, which reviews every case of deadly force used by public safety officials. The officers involved in the shooting — Joey Lefebvre and Ron Dunham from the Maine Warden Service and Thomas Park, a veterans’ affairs police officer — are on paid leave until the investigation is complete.

According to statistics provided by the AG’s office, police in Maine have used deadly force 82 times in the last 20 years, including Thursday. In 44 cases, the use of force resulted in death. In none of those cases was an incident of deadly force ruled not justified.

A spokeswoman for the AG’s office said the criteria for determining justification is simple: Did an officer reasonably believe that his or her life or the life of a third party was in imminent danger and that using deadly force was the only way to eliminate that danger? Rep. Donald Pilon, D-Saco, who last year cosponsored legislation that sought to improve the review process for incidents where deadly force was used, said Friday that the state’s criteria is too narrow. He wondered how anyone could question a police officer’s state of mind during a given incident. Pictures of heavily armed state police tactical team members in camouflage gear and face-paint do little to dispel the notion that some officers are too aggressive, he added.

Furthermore, the state’s review process does not examine events leading up to the shooting or whether alternative means could or should have been used. Some departments conduct their own internal affairs review of any police shooting, but that process is rarely public. It’s unclear whether that will happen in Popkowski’s case.

Kate Simmons, spokeswoman for the Attorney General’s Office, said additional details about Thursday’s incident are part of the investigation and would not be released. Simmons said it typically takes up to 90 days for her office to submit a report, which will be made public.

The only details known at this point are that Popkowski had a history of depression and that he was armed when police shot him. Witnesses have offered differing accounts of the incident.

Cases of deadly shootings by police are always tragic and often involve victims suffering from mental illness, Simmons said.

Pilon acknowledged the unpredictability of those with mental health issues but he said many incidents can be avoided. He recalled a case two years ago in South Portland when a young man, clearly distraught, engaged police in a lengthy standoff. After several hours, Michael Norton came out of his house armed with a knife in each hand. Police told him to drop his weapons, but he refused. Officers opened fire and killed Norton.

“The police all had protective gear,” Pilon said. “At what point do you have to take aggressive action? We need to at least get [police] to think about teaching cadets that you don’t always have to use your gun. There are other methods to diffuse a situation. It doesn’t always have to be a tragic ending.”

According to national statistics compiled by the U.S. Department of Justice, there were an average of 358 fatal deadly force incidents ruled justified per year between 1991 and 2008 with a high of 398 in 2007. The national data is based on voluntary reporting of individual agencies and therefore likely incomplete. Data on cases of unjustified deadly force by law enforcement agencies was not available.

Some agencies employ officers who are trained to intervene before deadly force is necessary. In recent years, more and more public safety agencies have added Tasers to an officer’s arsenal as a non-lethal alternative.

In some instances, victims try to commit what is known as suicide-by-cop, which means they want to be shot. In other cases, police are able to avoid conflict. Earlier this year, state police Trooper Michael Johnston came within moments of opening fire during a confrontation with a suspect in Bangor believed to be armed.

Either way, Pilon said, the review process for deadly force cases needs to be better. Even police can’t have a 100 percent record.

Last year, he cosponsored L.D. 1066, a bill that would require police departments to form incident review teams in the wake of police shootings that include members of the public. Pilon said successful lobbying of public safety officials watered down the bill that eventually passed.

Instead of a well-rounded panel that included members of the public, the bill was amended to give the chief executive officer of the agency reviewing use of deadly force discretion over who would be appointed.

“The police chiefs association and the state police felt threatened, so they created their own review board. But it’s all police on the board,” Pilon said.

Opponents of the bill, mostly law enforcement representatives, argued that people without backgrounds in law enforcement don’t have training in police procedure to judge tactics. Simmons pointed out that Brian MacMaster, head of the AG’s Investigations Division, testified neither for nor against L.D. 1066.

In testimony to the legislative committee, MacMaster referenced discussions by members of a task force created in 2008 by then-Attorney General Steven Rowe to examine the use of deadly force.

“The task force found no consistent deficit in training, procedures, or knowledge on the part of law enforcement that, if addressed, would have led to a different outcome,” MacMaster said, according to a transcript of his testimony. “The task force found that the law enforcement officers in these cases behaved in ways consistent with an understanding of potential mental health issues reasonable for the situations they were facing. With that said, however, the task force did find conditions that, if addressed, could decrease the incidence of situations requiring police to intervene with persons with mental illness under similar highly dangerous circumstances.”

If he’s re-elected in November, Pilon said he would submit another bill that examines the issue of deadly force by officers.