Buzzfeed News has released details from newly released investigative files regarding Parkland shooting suspect Nikolas Cruz. The evidence released by investigators are detailed testimonies by family members, former classmates, and others that tell a story of missed red flags.

Nikolas Cruz confessed to shooting and killing 17 students and faculty members [VIDEO] at Marjory Stoneman Douglas High School in Parkland, Florida on February 14. Before carrying out the massacre, Cruz threatened to shoot up the school and others.

Nikolas Cruz threatened several people, including a classmate's mother

While working as a cashier at a Dollar Tree in the summer of 2017, Cruz was approached by Giovanna Cantone, a local mother who had a daughter that also attended Marjory Stoneman Douglas, which Cruz had been expelled from after getting into a fight.

Cantone offered him advice about finishing his high school degree online or at another school.

His response shocked her. According to the Miami Herald, in her sworn statement, Cantone told prosecutors that Cruz replied, "'I can go shoot them and you know I can shoot you, too.'" Her daughter, Ina, was standing nearby and overheard his response, but both thought that he was only joking. Still, Cantone admitted to feeling frightened after the encounter.

A former classmate from Cruz's engineering class at the Parkland high school noticed that he would look up disturbing things online; In one incident, the classmate witnessed Cruz researching about how to make a nail bomb.

One student who identified herself as a close friend of Cruz, described how he would show off dead, mutilated animals at school.

"He’s like a hunter so he used to kill birds, squirrels, and cut their heads off," she detailed in a statement. Another student named Dana Craig said that Cruz threatened to kill her after she convinced her friend to stop dating him after he physically abused her. Craig and other students at Marjory Stoneman Douglas often discussed Cruz's behavior and whether or not they reported it.

Cruz's brother found disturbing content on his cellphone

Nikolas Cruz's brother, Zachary, told investigators about his brother's violent tendencies. Zachary Cruz admitted to once scrolling through the messaging app, Kik, on Nikolas's cellphone and seeing that his brother was texting himself about killing people at the high school. Zachary also told investigators that he would often hear his brother talking to himself about killing people. Zachary and neighbors testified that Nikolas would shoot guns in their house, and would shoot at chickens, buckets, and cans with a BB gun.

While Cruz was notorious for his behavioral problems and violent tendencies, most of his disturbing behavior was ignored.

The gunman even posted a video about becoming a school shooter on his YouTube page. CNN reported that someone close to Cruz reported his collection guns and knives and his mutilation of small animals to an FBI tip line and that the FBI admitted to not sharing the information with agents in Miami. As the nation and Parkland community continues to mourn the victims of the tragedy, the numerous missed red flags also raise the question of if the shooting could have been prevented.