An arrested person jumped from a Dallas police squad car onto R.L. Thornton Freeway on Saturday after police said the person gained control of the vehicle while an officer was inside.

Dallas police responded about 6:10 p.m. to an assist officer call on R.L. Thornton Freeway near Beckley Avenue.

According to a preliminary investigation, officers had arrested the person in the 2300 block of South Marsalis Avenue and were transporting the person to jail when the person gained control of the squad car with an officer inside, police said.

The officer regained control of the squad car before the person jumped out and onto the freeway, police said.

Dallas Fire-Rescue responded and took both the officer and the arrested person to a hospital for treatment. Police said investigators do not believe the person was struck by another vehicle.

Police did not immediately release the officer’s condition, the arrested person’s condition or details about the original arrest.

The investigation is ongoing.