LEWISTON, Maine (AP) — The independent commission announced by Democratic Gov. Janet Mills to investigate the shootings that claimed 18 lives in Maine last month includes former judges, prosecutors and mental health professionals, who were directed Thursday by the governor and attorney general to “follow the facts wherever they may lead.”

The governor formally created the panel with an executive order Thursday on the same day some victims and family members signaled their intent to sue with requests to 20 state and federal agencies to preserve evidence.

“The community of Lewiston, especially the victims and their families, have many unanswered questions. Why did this happen? How did the system fail? What changes are needed to ensure this never happens again?” said attorney Travis Brennan from Berman & Simmons, a Lewiston-based law firm.

The shootings at a bowling alley and a nearby bar on Oct. 25 in Lewiston killed 18 people and injured 13 others, making it the deadliest mass shooting in Maine history.

The independent panel announced by the governor and Attorney General Aaron Frey includes former Chief Justice Daniel Wathen along with other former state and federal judges and prosecutors, a forensic psychologist and an official at a private psychiatric hospital.

“As we have said, the complete facts and circumstances — including any failures or omissions — must be brought to light and known by all. The families of the victims, those who were injured, and the people of Maine and the nation deserve nothing less,” Mills and Frey said in a statement.

Critics have pointed to missed opportunities to prevent the tragedy because the alleged shooter, Army reservist Robert Card, 40, of Bowdoin, had been known to law enforcement for months as family members and fellow reservists became increasingly worried about his mental state along with his access to firearms.

Concern accelerated following an altercation with fellow Army Reserve members last summer while training in New York state, leading to a 14-day stay at a psychiatric hospital for Card. The concerns continued when Card returned to Maine, with one fellow reservist reporting that “he’s going to snap and do a mass shooting.”

Deputies visited Card’s home but he didn’t come to the door.

A week before the shooting, Card was working as a truck driver delivering bread to a location in Hudson, New Hampshire, when he said, “maybe you will be the ones I snap on,” according to redacted documents released Thursday. That incident happened on Oct. 19, but wasn’t reported until after the shootings.

Card’s body was found two days after the shootings in the back of a tractor-trailer in a nearby town. An autopsy concluded he died by suicide eight to 12 hours before his body was discovered.