(CNN) The couple who took in Florida school shooter Nikolas Cruz said they were devastated, furious and heartbroken about what he's done, and said they didn't realize they had a "monster" living under their roof.

James and Kimberly Snead told ABC's "Good Morning America" on Monday they are hurting for the families of the victims in the shooting at Marjory Stoneman Douglas High School in Parkland.

"We're devastated, and I can't imagine the pain they must be feeling, but we're very sorry they had this experience," said Kimberly Snead. "It never should have happened."

"Nothing I can say will heal them," James Snead said. "We hurt for them deeply."

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This is the second interview the couple, along with their attorney Jim Lewis, have given to the media. They first spoke with the Sun Sentinel, saying they were not aware of Cruz's social media presence. They took him in last Thanksgiving after their son asked if he could move in with them. Cruz's adoptive mother died in November of pneumonia, leaving him without parents. His adoptive father died of a heart attack more than a decade ago.

"He was very polite, he seemed normal," James Snead said of Cruz on ABC. "We knew he had one Instagram account. ... The other ones he had, we had no idea about."

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The couple was also unaware that he may have been cruel to animals. A CNN investigation found that Cruz was in a private Instagram group chat where he discussed killing small animals, and even posted a picture of a disemboweled frog. The Sneads are animal lovers who have two dogs and six cats, according to the Sun-Sentinel.

"There is no way I would let anybody in my house if I thought he was torturing animals at all," Kimberly Snead said. "We're learning a lot about all of this just the same as everyone else. We feel betrayed as well and just shocked. It crushed everybody's world in our community."

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Cruz also espoused racist, homophobic and anti-Semitic views in the group chat, the CNN investigation showed. The couple told the Sun-Sentinel they knew Cruz was lonely, depressed and a bit odd, but saw no warning signs of a coming massacre.

"We had this monster living under our roof and we didn't know," Kimberly Snead told the Sun-Sentinel.

But James Snead told CNN on Monday they knew Cruz "was depressed."

"He told us he was depressed," Snead said.

Snead said Cruz was "just trying to fit in ... didn't know what to say, or when to say or how to say it."

"So, he'd ask a lot of questions. He'd apologize a lot if we told him to do something," Snead said.

Since Wednesday's shooting, the Sneads told ABC, their life has been "a roller coaster of emotions."

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James Snead said their son feels betrayed and angry. He and Cruz had been friends, the Sun-Sentinel said.

"He had friends at that school," James Snead told ABC.

The Sneads last saw Cruz at the Broward County Sheriff's Office headquarters hours after the shooting Wednesday, where Kimberly Snead said Cruz apologized.

"I was just furious and heartbroken," Kimberly Snead said. "I can't process what he's done. This isn't the person we knew."