ST. PETERSBURG, Fla. — The St. Petersburg teen accused of stabbing and killing his grandmother is now being charged as an adult. 

The 13-year-old defendant, Javarick Henderson Jr., made his first appearance in court Wednesday. A lawyer was by his side.

(Spectrum Bay News 9 does not name juveniles who have been arrested unless they have been charged as an adult. Here is a link to our crime guidelines.)

Prosecutors are charging Henderson with first-degree murder.

Police say that about two weeks ago, Henderson stabbed 56-year-old grandmother Gloria Davis multiple times during a violent attack and killed her.

Detectives have not yet determined a motive for the gruesome crime.

The Pinellas County Sheriff’s Office released video of Henderson being booked into the adult jail Tuesday from juvenile detention.

A judge ordered that Henderson will be held without bond.

None of the teen’s family or friends showed up for the hearing.

The judge appointed a public defender to represent Henderson.

Spectrum Bay News 9 was unable to reach the teen's parents for comment.