Police in the US have been blasted by a report showing they could have prevented a tragic mass shooting if they had intervened previously when concerns were raised about the army reservist.

The report that came out on Friday said the police knew about Robert Card's mental health problems and could have stopped him before he shot 18 people in Lewiston, Maine on October 25. A report looked closely at what happened before the terrible shooting and how the police reacted, especially when they didn't act weeks earlier.

Sergeant Aaron Skolfield from the Sagadahoc County Sheriff's Office had been told five weeks before that Card was having a mental health crisis. He had attacked someone before and said he would shoot up the Saco Armory. The report said Skolfield should have started a "yellow flag" process to take away Card's guns while he was unwell.

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He exhibited concerning behavior prior to the tragic shooting spree (
Image:
Maine State Police)
Card, the Army reservist behind Maine's deadliest mass shooting, had a history of warnings (
Image:
Lewiston Maine Police Department)

Leroy Walker, whose son Joseph died in the shooting, thinks the report is right. "The commission said it straight out - that they could have done it, should have done it," said Walker, who works for the city council in Auburn.

Commission Chair Daniel Wathen emphasised that their work was ongoing and aimed to give important information to policymakers and law enforcement. "Nothing we do can ever change what happened on that terrible day, but knowing the facts can help provide the answers that the victims, their families, and the people of Maine need and deserve," Wathen said in a statement.

18 victims of the tragedy - Maine's deadliest shooting (
Image:
Maine State Police/AFP via Getty)

Ben Gideon, a lawyer for the victims, thinks it focused too narrowly on the actions of the sheriff's office. He said: "I was a little disappointed that the committee didn't take a wider view of the issues that start as far back as May." He also expressed his hope that the report would make the shooter's health records available to victims and the public, which it did not.

The commission was led by a former chief justice of Maine's highest court and included a former US attorney and the former chief forensic psychologist for the state. It was put together by Democratic Governor Janet Mills and Attorney General Aaron Frey, and the commission held seven sessions starting in November.

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Police should have seized his guns, a report said (
Image:
FACEBOOK)

During the sessions, the commission gathered testimony from law enforcement, survivors, victims' family members, and members of the US Army Reserve to explore preventive measures and necessary changes going forward. While a final report is due in the summer, the commission plans to schedule additional meetings to further examine the circumstances surrounding the tragedy.

Card, who was found dead by suicide after a two-day search, had been a subject of concern to law enforcement and his family due to his deteriorating mental health and potential for violence. Despite warnings from relatives and fellow service members about his behaviour, access to firearms, and escalating paranoia, interventions were not implemented effectively.

Lewiston's Chief of Police David St. Pierre speaks to the media about Robert Card (
Image:
Getty Images)

Testimony from law enforcement officials revealed the challenges posed by Maine's yellow flag law in removing firearms from potentially dangerous individuals. Skolfield recounted difficulties in engaging with Card during a welfare check in September, citing legal limitations.

Rachael Sloat, who was set to marry Peton Berwer Ross who died in a shooting, shared her pain with the committee. She said every time their little girl, who is only 2 years old, asks for her daddy, it breaks her heart.

"Where are you? " she asked. "Every politician, every member of law enforcement, every registered voter in the country - I want you to hear those words. 'Where are you? ' Because my fellow Americans, where are you? We failed my little girl."