PARKLAND, Florida: A Florida social services agency conducted an in-home investigation of Nikolas Cruz after he exhibited troubling behaviour nearly a year and a half before he shot and killed 17 people at his former high school in Florida, a state report shows.

The agency, the Florida Department of Children and Families, had been alerted to posts on Snapchat of Cruz cutting his arms and expressing interest in buying a gun, according to the report. But after visiting and questioning Cruz at his home, the department determined he was at low risk of harming himself or others.

The report is the latest indication that Cruz was repeatedly identified by local and federal agencies as a troubled young man with violent tendencies.

The FBI conceded Friday that it had failed to investigate a tip called into a hotline last month by a person close to Cruz identifying him as a gun owner intent on killing people, possibly at a school. The local police were called to Cruz’s house many times for disturbances over several years.

Cruz also worried officials at his former school, Marjory Stoneman Douglas High in Parkland, who on at least one occasion alerted a mobile crisis unit to get him emergency counselling, according to the state report.

Broward County Public Schools disciplinary records obtained Saturday by The New York Times show Cruz had a long history of fights with teachers, and was frequently accused of using profane language with school staff. He was referred for a “threat assessment” in January 2017, the last entry in his record, two months after the Department of Children and Families closed its separate investigation into Cruz’s worrisome behaviour.

‘Multisystem failure’

Howard Finkelstein, the Broward County public defender, whose office is representing Cruz, said the report was further evidence that Cruz needed serious help long before the shooting, but did not get enough of it.

“This kid exhibited every single known red flag, from killing animals to having a cache of weapons to disruptive behaviour to saying he wanted to be a school shooter,” Finkelstein said. “If this isn’t a person who should have gotten someone’s attention, I don’t know who is. This was a multisystem failure.”

The state agency investigated whether Cruz intended to harm himself in September 2016, when he made the alarming social media posts after an argument with his mother. Cruz, who had depression, was upset over a break-up with a girlfriend, his mother, Lynda Cruz, told investigators. The report does not say who called in the complaint, which was given “immediate” priority.

The report shows that investigators closed the case about two months later. The agency determined that the “final level of risk is low” — an analysis that one of Cruz’s counsellors at his school felt was premature — because his mother was caring for him, he was enrolled in school and he was receiving counselling. By the time of the shooting, however, Cruz had lost at least two of those elements: His mother was dead, and he had left Stoneman Douglas High School. It is unclear if he was still seeing a counsellor.

On Wednesday, Cruz, 19, showed up at Stoneman Douglas and unleashed more than 100 rounds from a semi-automatic AR-15 rifle he purchased last February, five months after the state investigation closed. As of Saturday evening, two Broward hospitals were still treating four patients in fair condition, according to Jennifer Smith, a spokeswoman.

Guilty plea

The office of Finkelstein, the public defender, suggested that it had offered prosecutors a guilty plea in exchange for a life sentence without the possibility of parole.

“Everybody knows he is guilty. What we are saying is, let’s put him away for life,” Finkelstein said. “We are not saying the death penalty is not justified; we are saying, let’s not put this community through the trauma and pain of a trial knowing that, three years down the road, one juror could keep him from being put to death.”

In Florida, the death penalty requires a decision by a unanimous jury.

Michael J. Satz, the state attorney, said prosecutors would announce their position on the death penalty “at the appropriate time.”

“This certainly is the type of case the death penalty was designed for,” Satz said in a statement. “This was a highly calculated and premeditated murder of 17 people and the attempted murder of everyone in that school.”

Cruz’s school disciplinary records show he attended at least six schools, including Cross Creek School, a school for students with emotional problems; Dave Thomas Education Center, an alternative high school for at-risk youths; and an adult education Centre. He was first identified as developmentally delayed in 2002, when he was 4 years old.

In incidents that began in 2012, when Cruz was 13, he was disciplined for being disobedient and unruly. In 2013, the records suggest, he was counselled for making a false 911 call.

Prolonged absences

He was suspended several times in the 2016-17 school year, his last year at Stoneman Douglas, and was frequently reported for prolonged and unexplained absences. In September 2016, he was suspended for two days for fighting, only to return and get suspended again nine days after the fight, this time for hurling profane insults.

That same month, the Department of Children and Families began its investigation into Cruz. The investigation, first reported by The Sun-Sentinel of South Florida on Friday, was obtained by The Times on Saturday. The state agency had petitioned a court Friday to make the confidential records public, but the court has yet to do so.

“Mental health services and supports were in place when this investigation closed,” Mike Carroll, the secretary of the Department of Children and Families, said in a statement. Cruz was investigated as an adult, and the investigation appeared aimed at determining whether he was being neglected.

Agency investigators identified Cruz, who had turned 18 a few days earlier, as a “vulnerable adult due to mental illness”.

In addition to depression, Cruz had autism and attention-deficit hyperactivity disorder, the report said. He was regularly taking medication for the ADHD. It was unclear whether he was taking anything for the depression, according to the report.

After the argument with his mother, an investigator visited the family’s home in Parkland, which was clean, clutter-free and did not present any foul odours. The investigator did not see the cuts on Cruz’s arms: He was wearing long sleeves.

“Mr Cruz stated that he plans to go out and buy a gun,” the report states. “It is unknown what he is buying the gun for.”