A prosecutor in upstate New York says a Florida teen shot and stabbed his grandmother to death before fleeing north toward Canada.

Logan Mott, 15, was set to be arraigned Wednesday in family court in Erie County, New York, where he was pulled over on November 24, when he made a wrong turn on a bridge that spans the United States and Canada. That hearing will now take place in adult court on Friday. Mott will be charged with murder in the death of his grandmother, 53-year-old Kristina French.

Mott, a freshman at Sandal Wood High in Jacksonville, has denied killing his grandmother.

The Mayport woman was positively identified on Monday by the Jacksonville Sheriff’s Office. Border Patrol allegedly found three guns and a knife with what appeared to be blood on it in the car Mott was driving after they detained him on the Peace Bridge, which connects the U.S. and Canada.

Mott and his grandmother Kristina French, 53, were reported missing on Nov. 21 when they didn’t pick up his father and the father’s girlfriend after the couple arrived back to the Jacksonville area from a vacation. The two took an Uber back to their Neptune Beach home to find it ransacked with the door open and guns missing from a gun safe, and called police.

The teen, who is insulin-dependent, was initially feared to be in danger and was the subject of a Florida missing child alert. But when French’s buried remains were uncovered in the home’s backyard Thursday along with evidence of “possible criminal violence” inside the home, according to the Jacksonville Sheriff’s Office, Mott was named as a person of interest and called “armed and dangerous.”

An arrest warrant for murder, charging Mott as an adult, was issued by a Florida judge Tuesday.

“We didn’t want to take a chance a family court judge would release the boy to his mother,” said prosecutors. “Whatever delay tactic they want to take, all they’re doing is keeping the guy in custody here in New York a little while longer.”

The judge ordered Mott held without bail, ruling that the teen is a flight risk.