(NEW YORK) -- An independent report released Thursday found that local authorities responded reasonably to concerns about the declining mental health of Maine shooting suspect Robert Card reported in the months before the deadly mass shootings.
Card, a 40-year-old Army Reservist, had a well-documented series of warning signs that his psychological state was on a sharp decline in the months leading up to the Oct. 25 shootings, when he allegedly opened fire at a bar and bowling alley in Lewiston, claiming 18 lives and injuring 13 more. Card was found dead from a self-inflicted gunshot wound two days after a massive manhunt.
As his mental health declined, the suspect's family reported they were concerned for his well-being and that he had access to firearms, according to documents previously obtained by ABC News. A "yellow flag" order -- which would temporarily restrict access to guns during a mental health crisis -- was never completed for him; firearms recovered from the shooting rampage were purchased legally by Card, officials said.
The Sagadahoc County Sheriff's Office responded to concerns about Card's mental health over several days in May and September. The 93-page independent report found that the response was "reasonable under the totality of the circumstances."
The deputy and sergeant respectively involved in the May and September response "each diligently explored the nature and extent of the concerns about Mr. Card's mental health and that it was reasonable for them to conclude under the totality of the circumstances both that Mr. Card did not then pose an imminent risk of self-harm or harm to others," according to the review.
The review also found that "there were insufficient grounds to take Mr. Card into protective custody or to take other actions, and that deferring the monitoring of Mr. Card's wellbeing, including guidance toward a mental health evaluation and treatment, to third parties while emphasizing the availability of Sheriff's Office resources if they should be needed thereafter, was objectively reasonable."
The report recommends that the sheriff's office enhance its mental health-related training programs, take "full advantage of its partnership with the newly available mental health liaison resource" and explore the creation of a mental health response team.
The Sagadahoc Sheriff's Office said it has "committed to implementing the recommendations."
"The mass shooting on Oct. 25 in Lewiston has changed the community and our state forever. Our focus remains on supporting those who were hurt and the families and friends of those who were killed," Sagadahoc Sheriff Joel Merry said in a statement Thursday upon releasing the report. "At the same time, it's critical for our agency to look objectively at our actions and make changes to help reduce the risk that something like this will happen again."
The independent review was initiated by the Sagadahoc County Sheriff's Office on Nov. 3. It was conducted by Michael A. Cunniff, a former supervisory special agent for the U.S. Drug Enforcement Administration.
Additional reviews of the mass shooting are underway. Maine Gov. Janet Mills and Maine Attorney General Aaron Frey announced in November that a seven-member commission made up of legal, investigative and mental health experts will have the authority to probe all aspects of the shooting.
ABC News' Sasha Pezenik contributed to this report.