A 15-year-old boy who was the subject of a Florida Missing Child Alert and then sought as a person of interest in his grandmother's death is in custody.

Logan Mott was captured as he tried to enter Canada from Buffalo, New York, according to the Jacksonville Sheriff's Office.

State officials had issued the missing child alert for Mott of Neptune Beach after his father reported the boy and his grandmother, 52-year-old Kristina French, were missing after his house was ransacked and firearms were missing, First Coast News reported.

On Friday, however, a body was found in a grave site at the home. Officials are waiting for an autopsy to positively identify the body, but they believe it is French.

The Jacksonville County Sheriff's Office says Mott is wanted for the theft of French's silver 2015 Dodge Dart with Florida tag DLLT42. He is also a person of interest in French's death.

They released a photo of Mott with short hair and said they thought he was in the Northeast because he was seen in Pennsylvania on Thursday.

For more, read the First Coast News report.