Nikolas Cruz, the suspected gunman in Wednesday’s shooting at a Florida high school that left at least 17 people dead, was living in a mobile home with a student for the last three months, his attorney said.

A portrait of the suspected gunman began to emerge of the former Marjory Stoneman Douglas High School student in the hours following the deadliest school shooting since Sandy Hook.

Police said Nikolas Cruz, 19, allegedly opened fire at Marjory Stoneman Douglas High School in Parkland, Florida, on Wednesday.

Cruz was arrested without incident just over a mile from where he was suspected of killing more than a dozen people, the Broward County Sheriff’s Office said.

Police said Cruz used an AR-15 and had multiple magazines on him during the shooting. Cruz’s attorney Jim Lewis told the South Florida Sun Sentinel that the firearm was legally bought and already own the gun when he moved in with a friend, a junior at the Parkland high school, three months ago.

“It was his gun,” Lewis told the newspaper. “The family made him keep it in a locked gun cabinet in the house but he had a key.”

The mobile home in Lantana, about 30 miles north of Parkland, where Cruz lived with the friend drew a police presence late Wednesday, according to WPEC-TV.

The Broward County Sheriff’s Office, the Bureau of Alcohol, Tobacco, Firearms and Explosives and the FBI were investigating the mobile home, the Palm Beach Post reported. Authorities were reportedly notified of a possible explosive device at the property.

Cruz was adopted, along with his younger brother Zachary, were adopted by Lynda and her husband Roger Cruz after the couple moved from Long Island, N.Y. to Broward County.

Lynda Cruz died Nov. 1 of pneumonia and Roger had