(CNN) The Florida couple who took in school shooter Nikolas Cruz knew the depressed 19-year-old owned multiple guns, but felt safe knowing the weapons were under lock and key.

James and Kimberly Snead told CNN's Alisyn Camerota on Monday that despite being depressed, the teen was doing really well in school, and that Cruz "was proud of what he was doing," sharing his grades with the family and working toward his high school diploma.

Kimberly Snead says Cruz had told their son two weeks ago that "he's the happiest" he had been in recent times.

The Sneads have been speaking to media along with their attorney Jim Lewis.

James Snead says before Cruz moved in with them, he had seen him around the house on occasion because he was a friend of the couple's son.

"I'd met him a couple times before," he said, adding Cruz "stayed at the house with my son, spent the night." Snead remembers that Cruz was "very respectful then."

The weapons 'really didn't concern me'

The Sneads knew Cruz had multiple weapons and made him get a gun safe before he could move in with them last Thanksgiving after their son asked if Cruz could stay with them. Shortly before that, Cruz briefly lived with a family in the nearby town of Lantana, Florida.

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James Snead told CNN that "the family friend he was staying with had a toddler. And so it just -- it wouldn't work. Because he didn't have a gun safe, so I don't know -- I don't know if [the guns] were in a bag. I don't know if they were leaning against a wall. But it just -- it wasn't working that way."

Cruz's adoptive mother died in November of pneumonia. His adoptive father died of a heart attack more than a decade ago.

Cruz had also told the Sneads "he was depressed" and had shown interest in seeking medical help for his symptoms.

Kimberly Snead says the mix of depression and weapons didn't worry the couple. "To me, the depression was more stemmed from loss -- losing his mother, not from all the things they said about him being bullied, or by -- things that happened in school" she says, adding that with the gun safe, "everything'd be locked up, it really didn't concern me."

She also says she had started the process of getting him to see a counselor.

"They were gonna start the insurance processes to see what would be covered, and he was gonna start going," she said.

James Snead added "ironically, it probably would've been this week."

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When it came to the gun safe Cruz purchased, the couple thought they had full control of it.

"I thought I had the only key. And I had control over it," James Snead recounts, adding on one occasion he had told Cruz he wasn't allowed to access the weapons.

Though they don't know how many weapons Cruz owned -- and acknowledge there were a few, including pellet guns -- they had asked him to provide paperwork proving the guns were purchased legally.

A law enforcement source briefed on the investigation told CNN that Cruz had obtained at least 10 firearms , all of them rifles. Investigators are trying to track the purchases, which Cruz appears to have made in the past year or so, the source said.

The couple also says the cell phone video showing Cruz dressed in boxer shorts, shooting what appeared to be a BB gun in a backyard, was not from his time at their house.

In the dark about social media footprint

the Sun-Sentinel. 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 an interview withthe 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 to the newspaper. "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."

In the interview with CNN, she said she had no idea the depth of Cruz's social media footprint.

"I don't have an Instagram account, so I didn't know any of that. So -- I mean, I have Facebook, but not Instagram," she added. The couple says their son was aware of one of Cruz's Instagram accounts, but it was not one of the accounts that have since surfaced.

'We feel for' the victims

The Sneads say that while they are heartbroken for all the victims, they know no words can comfort the families.

"We feel for them, " James Snead said. "Our heart aches for them. And hopefully something good will come out of this."

"I am proud of the students taking up for their own -- and demanding changes. I think that's very important. And maybe somebody will listen," James Snead told CNN, adding he is not opposed to expanded background checks.