A Florida man facing dozens of sexual assault charges in connection to the February killing of 13-year-old Madeline "Maddie" Soto is Robert Brownnow charged with capital murder in her death, court records show.

Stephan Sterns, already accused of 60 child sex abuse-related charges, was charged with first-degree murder on Wednesday, according to Osceola County Circuit Court records. The Kissimmee Police Department and the Orange County Sheriff's Office initially arrested Sterns in connection to the case on Feb. 29.

Madeline "Maddie" Soto disappeared on Feb. 26 from her home in Kissimmee, a city about 20 miles south of Orlando. The girl's body was found on March 1.

Sterns was the last person to see Maddie alive, according to an X post by the Orange County Sheriff's Office.

He's slated to be arraigned on the new charge Monday before Judge Keith Carsten.

If convicted of capital murder, Sterns faces the death penalty.

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What happened to Madeline Soto?

The girl was last seen wearing a green sweatshirt, black shorts, and white Crocs, the Kissimmee police, the lead investigation agency on her death, said Friday. The Orange County Sheriff's office said that evidence reported she was "never dropped off near her school" on the morning she vanished.

Video footage from the day she disappeared shows Sterns "discarding items in a dumpster at the family’s Kissimmee apartment complex" at 7:35 a.m., the sheriff's office reported on X, adding investigators found Madeline's backpack in the dumpster.

Footage then shows Sterns allegedly returning to the family's home at 8:20 a.m. with "Madeline visible in the car," but investigators think she was already dead.

During the sheriff's office's investigation into Madeline's disappearance, detectives found "disturbing images when they forensically examined Sterns’ phone" − some which he reportedly attempted to delete.

The alleged sex crimes, detectives reported, took place at Madeline's home, the agency reported.

Stephans Sterns jailed without bond in Florida

Sterns remained jailed without bond Friday, online records show.

As of Thursday, an attorney of record for the first-degree murder charge Sterns faces was not posted online.

Contributing: Jonathan Limehouse and Saman Shafiq

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.