The family who took the Florida school shooting suspect into their home after his mother died have labelled him a “monster”.

Kimberley and James Snead said Nikolas Cruz was lonely and depressed, but they saw no warning signs.

The 19-year-old is accused of killing 17 and leaving more than a dozen injured, at the Marjory Stoneman Douglas High School in Parkland, a small city about 50 miles north of Florida.

"We had this monster living under our roof and we didn't know, "Ms Snead told the South Florida Sun Sentinel. "We didn't see this side of him."

Mr Snead added: “Everything everybody seems to know, we didn’t know. It’s as simple as that.”

Mr Cruz went to live with the Snead family after his adopted mother died of pneumonia last November.

Their son asked whether he could join them in the family home.

As well as providing him with a roof over his head, they registered him in adult education classes and helped him get a job at a local pound shop.

They were forced to teach him basic chores such as how to cook, use the microwave, wash his clothes and tidy up after himself.

"He was very naive. He wasn't dumb, just naive," Mr Snead, an army veteran, said. "I told him there’d be rules and he followed every rule to the T."

The parents said they were alright with the teenager storing guns in the house as they long as they were kept in a gun safe. They told Mr Cruz he had to ask permission before taking out the guns.

Mr Snead told the paper he thought he was the only person who possessed a key to the safe, but he now thinks Mr Cruz kept a key for himself.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

While Mr Cruz has not yet entered a plea, an arrest affidavit alleged that he confessed to authorities he was “the gunman who entered the school campus armed with a AR-15 and began shooting students that he saw on the hallways and on the school grounds”.

In the meantime, tales of heroism during the shooting have emerged, including that of Anthony Borges, who reportedly placed his body between the shooter and fellow students.

Carlos Rodriguez, said he survived the massacre because of his best friend Anthony's heroism.

"None of us knew what to do. So, he took the initiative to just save his other classmates," Carlos told ABC's Good Morning America.

He said that after gunfire erupted Anthony and his fellow classmates made a dash to hide in a classroom. According to Carlos, Anthony was the last of 20 students who escaped into a room and was trying to lock the door when he was shot.

He said he used his body as a human shield in the doorway and managed to put his body between the bullets and his classmates - who all survived wholly uninjured.

Anthony’s father said his son was shot a total of four times – taking bullets to the back and both of his legs – but managed to survive what was the deadliest school shooting since a gunman opened fire at Sandy Hook Elementary.

“He’s my hero,” Roy Borges, his father, said.