The Neptune Beach Police and the Jacksonville Sheriff's Office - where Mott's father works as a correctional officer - launched an investigation that uncovered "possible criminal violence inside the home", CBS reported.
Lendvay said a warrant was issued for the teen's arrest on an auto theft charge.
Florida police are looking for a missing teenager after his grandmother's body was found in a shallow grave in a back yard and his father's home was ransacked and guns taken.
The burial site was excavated on Friday and authorities later identified the body as French's. French's home was also ransacked and her weapons and 2015 Dodge Dart were missing.
Logan Mott, 15, was last seen in the area of the 400 block of Seagate Avenue in Neptune Beach.
Mott should be considered armed and risky, he said.
The teen is considered armed and risky, and police have advised the public against approaching him or the vehicle.
-Canadian border as he tried to leave the country from Buffalo, New York.
"We are alleviated that he is sheltered and in guardianship and we simply request everybody to give us an opportunity to deal with what happened", the high schooler's mom, Carrie Campbell-Mott said in an announcement to Action News Jax.
She added that "no matter what, Logan is our child and we love him and are standing by him to help in any way".
She wrote on social media that he was dependent on insulin and expressed worry that he might not have access to it.
Regarding the conversation with Logan, she told News4Jax: 'There just wasn't any indication that there was anything wrong, nothing. It was just a normal conversation'.