(NewsNation) — The body of Florida mom Cassie Carli was found in a shallow grave at an Alabama barn, authorities announced Sunday.

Carli’s body was found by officers who had a search warrant nearly one week after she went missing, the Santa Rosa County Sheriff’s Office said during a Sunday news conference.

Carli’s ex-boyfriend has been arrested on charges of tampering with evidence, according to the Sheriff’s Office.

Marcus Spanevelo was arrested by the Tennessee Bureau of Investigations and the Tennessee Highway Patrol in Lebanon, Tennessee, where he is being held on the following charges:

• Tampering with evidence
• Giving false information concerning a missing persons investigation
• Destruction of evidence

Santa Rosa County Sheriff Bob Johnson says they are working to extradite Spanevelo back to Florida and is expecting more charges to be filed following tomorrow’s autopsy.

“Since we’ve been dealing with him he’s been acting like a dirtbag,” Johnson said. “He never cooperated at all with us. That goes a long way. Think about it, it’s your baby’s mother and she’s missing, and you’re not going to cooperate with authorities. That’s kind of telltale”

Carli was last seen Sunday night in a parking lot picking up her 4-year-old daughter Saylor from Spanevelo, according to investigators.

This took place at Navarre Beach — a small Florida town on the Gulf of Mexico.

Saylor was found safe with Carli’s ex across the border in Alabama the next day.

Check back for updates as this story is developing.

NewsNation affiliate WFLA contributed to this report.