When the Snead family took Nikolas Cruz into their home last November, they thought of him as one of their own.

Now they’re trying to recall any warning signs they might have missed.

"The Nik we knew was not the monster he turned out to be," James Snead, whose son befriended Cruz, told NBC News.

Cruz, 19, is charged with the premeditated of murder 17 people at Marjory Stoneman Douglas High School, which reopens next week. He confessed to police that he was the gunman in the shooting, according to a Broward Sheriff's Office affidavit.

Just three months earlier, Cruz moved in with the Sneads after his mother, Lynda Cruz, died of pneumonia. They said he was depressed after losing his mother, but no red flags ever went off about his behavior.

For the majority of the time Cruz lived with the Sneads, they say they treated him like family.

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"When we went out to dinner, he went out to dinner with us. When we went to a friend's house, he went with us. He was part of our family," said James Snead, later adding that Cruz told him that his time with the family was the happiest in his life.

Snead and his wife, Kimberly, described Cruz as polite and "normal," saying they set rules for the teen, which he followed to the letter. If he left a candy wrapper or dish out, Kimberly Snead said Cruz behaved as if he was "afraid to be in trouble."

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"All the friends that have met him they couldn't believe it was him. They were in just as much shock as we were, being his personality that they knew of him, they couldn't believe he did it because he was timid and quiet, and socially awkward," Kimberly Snead said.

They said reports from the Florida Department of Children and Families about Cruz were never brought to their attention.

In 2016, Cruz was held for psychiatric evaluations after he sent out a Snapchat video in which he cut his arms and said he wanted to buy a gun, according to a Florida Department of Children and Families investigative report.

However, after being evaluated by Henderson Behavioral Health professionals, the decision was made not to hospitalize him. Additionally, the report noted that in 2015 Cruz had a “Nazi symbol drawn on his book bag” and “hate signs on a book bag stating, ‘I hate n------.’”

Before she died, Lynda Cruz told investigators during the 2016 incident that her son had ADHD, depression and autism, according to the DCF report. She also told investigators her son took medication he was prescribed.

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She also told officials that her son did not own a gun beyond an airsoft gun. She said that there “has never been any issues with other races or issues with racism in her family."

The Sneads said they knew Cruz had guns and were OK with it. There was a gun safe and James Snead believed he possessed the sole key.

Initially after receiving a phone call from his son on Wednesday about a shooting at school, James Snead said he didn't think it could have been Cruz responsible. He then received a call from a SWAT captain asking about the whereabouts of his son "Nikolas Cruz."

He said after the description of the shooter came out it began to sink in that the teen had accessed his gun safe. James Snead called the SWAT captain back and told him to go to his home and make sure his wife was safe.

Kimberly, who works as a neonatal ICU nurse, was sleeping before an evening shift at home when the shooting happened.

"I went to the door and [police] had guns on me, tell me put my hands in the air, 'Are you alone in the house?'" Kimberly Snead said. Police broke the news of the shooting to her as they searched the home.

After Cruz was arrested, James and Kimberly Snead were taken to the sheriff's office where they first laid eyes on the teen they had opened their home to. James had to hold Kimberly back.

"We didn't speak with him, I more of yelled at him," Kimberly said. "I was actually going to strangle him. I wanted to go after him. I tried, I guess."

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The only words she could utter: "Really, Nik? Really?"

James said he heard Cruz mumble an apology as he was pulled away.

"This kid was going through a lot and ... I'm not defending anything he did. Please don't think that. Absolutely not. He was broken and there were so many things that we are now learning. We didn't see this in our house. We were trying to help out a depressed kid who lost his mother," Kimberly Snead said.