A sheriff’s deputy from Miami-Dade County, Florida, was detained by federal authorities on Wednesday following charges of child exploitation.

The U.S. Attorney’s Office in Florida’s Southern District announced that Carle Miranda Blum, a 51-year-old deputy from the Miami-Dade Sheriff’s Office, faces accusations linked to the receipt and creation of images depicting the sexual exploitation of minors. Blum allegedly exchanged numerous explicit videos with a 17-year-old girl, with whom she was reportedly involved in a physical relationship. More details can be found in the complete report.

Blum was accused of recording herself engaging in the illicit acts with the underage girl and traveling across state lines to see her. And when the “relationship” hit the rocks, Blum allegedly threatened to kill the girl.

According to a criminal complaint obtained by independent news outlet WPLG, the sheriff’s office received a tip on July 14 that Blum was engaged in a relationship with an underage girl. When the girl attempted to board a flight to Miami — the day after she turned 18 years old — she was held under the Baker Act before she got on the plane, the complaint said. Blum retrieved her bags at the airport.

The witness told authorities that the girl’s mental health “had significantly deteriorated” over the course of the year she was allegedly involved with Blum.

Once authorities gained access to the teenager’s cellphone, they allegedly found many graphic videos depicting Blum with the girl, including two in which Blum was allegedly “violently choking” the teenager.

Further investigation into the alleged messages exchanged between Blum and the girl led authorities to believe that their correspondence was “romantic or sexual in nature.” Blum allegedly “continuously provided a ‘count down'” to the girl’s 18th birthday and promised to marry her, referring to the underage girl as her “wife.”

The complaint reportedly cited messages between Blum and the girl going back to February, including explicit photos and videos sent to Blum from the girl. Blum’s texts allegedly verged on being violent, including one that said, “I really need to RAPE your a—.”

When the relationship hit a rough patch and the girl attempted to break it off, Blum’s reactions were allegedly explicitly violent. One text read, “Leave me and see what happens.” Another read, “I will f—ing drive my favorite knife thru your throat and watch you [die] slowly. I swear on my [grandparents].”

According to WPLG, the complaint stated that authorities learned that Blum was planning on flying up to see the girl in Atlanta, Georgia, once she was out of the hospital. Blum was arrested in Atlanta on Wednesday.

In a statement obtained by local CBS affiliate WFOR, Miami-Dade Sheriff Rosie Cordero Stutz called the charges “very disturbing,” and “a betrayal of the badge, the public trust, and the oath we swear to uphold.” Cordero Stutz added, “The actions alleged stand in direct opposition to everything we represent as law enforcement officers and as human beings.”