Friends, family and neighbors were worried about Nikolas Cruz. So were social workers, teachers and sheriff's deputies in two counties.

As classes at Marjory Stoneman Douglas High School resumed two weeks after the shooting rampage that left 17 people dead, it is increasingly clear that Cruz, the alleged gunman, was deeply troubled.

The 19-year-old was the subject of dozens of 911 calls and at least two separate tips to the FBI. He also came to the attention of the Florida Department of Children and Families. Despite warning signs stretching back over a decade, no one intervened to stop the Valentine's Day shootings.

Many calls to the police

Cruz and his younger brother were adopted by Roger and Lynda Cruz. The family bought a sprawling house in the affluent Fort Lauderdale suburb of Parkland, Fla., in 1996. Roger, the patriarch, died when the boys were young, leaving Lynda to raise the children on her own.

When Cruz was just 10 years old, his mother called the police to the house. That call in 2008 was the first of dozens of times over the next decade she would summon law enforcement, often for help keeping her sons under control.

Sheriff's deputies were called to break up fights between Cruz and his brother. Neighbors in their community recall seeing squad cars in their driveway frequently.

At first, the problems seemed minor.

In November 2008, according to a list of service calls to the family residence released last week by the Broward Sheriff's Office, deputies responded to a report of Cruz "throwing a rock back at other juvenile."

By 2013, according to that list, the calls to the deputies began detailing more violence. In November of that year, Lynda said she was thrown against a wall because she took away an Xbox gaming system. In November 2014, deputies report Cruz used a BB gun to shoot a chicken.

By early 2016, deputies were called after a neighbor's son saw a disturbing Instagram post that seemed to suggest Cruz "planned to shoot up the school." At the time, deputies concluded that Cruz owned knives and a BB gun. They passed along that information to a school resource officer at Stoneman Douglas, but it is not clear whether any other steps were taken.

It is one of several incidents now under further investigation by the sheriff's office.

Of the 23 incidents deputies responded to at the Cruz residence, 18 of them involved Nikolas Cruz, according to the sheriff's office. The office says that "none appeared arrestable under Florida law."

At some point, money became a problem for the Cruz family. Lynda sold their Parkland home in early 2017 in a short sale.

"I saw Nikolas, and I said are you moving?" said Helen Pasciolla, a neighbor who lived across the street from the family. "And he said, 'We can't afford to live here anymore.' "

In November, Lynda died of complications from the flu. Cruz went to live briefly with a family friend, Roxanne Deschamps, outside Palm Beach, Fla.

But that situation did not work out well.

In 911 tapes released last week by the Palm Beach County Sheriff's Office, Cruz said he got in a fight with Deschamps' son. And he talked about his mother's death.

"The thing is, I lost my mother a couple days ago. So like, I'm dealing with a bunch of things right now," Cruz said. "I kind of got mad. And I started punching walls and stuff and a kid came at me and threw me on the ground. And he kicked me out of the house."

In a separate call to 911, Deschamps told the dispatcher that she was afraid Cruz would come back to the house with a gun and that he demonstrated violent behavior in the past.

"He put the gun on the head of his brother before. So, it's not the first time. And he did that to his mom. It's not the first time he's put a gun on somebody's head," Deschamps said on the 911 recordings.

No arrests were made, according to the police report. A sheriff's deputy picked Cruz up from a nearby park and returned him to the Deschamps home.