The individual, who has not been named in reports of the incident, is currently in the hospital receiving treatment for life-threatening injuries.
The victim's gender identity also has not been publicly disclosed.
"I don't know how this person identifies and, obviously, we want to be respectful of how this person identifies himself," JSO Assistant Chief Brien Kee told the local Fox affiliate. Police identified them as male, but neighbors say the victim is female.
Due to the victim's condition, police have not been able to speak with them or identify family.
According to police, the victim was tied by the ankles to the bumper of the car and dragged for two blocks before the rope was cut. Video footage of the incident exists, but police will not release it due to the graphic content. Kee called the footage "horrendous."
On Sunday, the Florida Times Union reported that police arrested 34-year-old Eric Shaun Bridges and charged him with attempted murder in the incident. The minivan involved in the attack had been reported stolen, and homicide investigators spoke with neighbors who led them to the vehicle and the suspect.
The Sheriff's Office also announced an arrest in another murder of a trans woman in Jacksonville.
Celine Walker was shot and killed by Sean Bernard Phoenix in 2018, police say. Though they recovered DNA evidence from the crime scene, it took a year to track the suspect down. Phoenix has since admitted to the shooting.
Although trans women of color, particularly Black trans women, have faced a wave of killings and attacks around the country, Jacksonville has been particularly hard hit in recent years. In 2018, three women were killed and a fourth was attacked. In addition to Walker, Cathalina James and Antash English lost their lives.
Although trans people are disproportionately targeted for violent crime, Florida does not extend hate crime protections on the basis of gender identity, while Jacksonville is the largest U.S. city without an LGBTQ+ inclusive nondiscrimination law on the books.
The Sheriff's Office is asking anyone with information about the attack to call 904-630-0500 or Crime Stoppers at 866-845-TIPS (8477).