Suspect
They headed straight back to the BAU to work on their new case. Garcia immediately got to work on the footage they'd managed to get from the hospital. She was soon able to get the licence plate of the cab and through facial recognition software pull out a name.
He was one Ethan Carter and she handed over the address. When they got there they found him playing video games blankly. When he saw them he just got up and let them arrest him. It was obvious by this action there had to be a more domineering partner involved in this.
They just hoped they'd get answers from Ethan. They left him to sweat in an interrogation cell while they called JJ to come and interview him. Dave wanted her to interview him as she was maternal due to being a mother. From the way he'd acted they believed he felt like he had a loyalty to someone that he couldn't break.
It was clear that whoever it was had been using him. They'd conditioned him too such a state that he would submit to anyone. They'd read that he and his sister had been abused by their mother until she died of cancer a few months ago. Their mother had been obsessed with their father to the point he slapped a restraining order on him a few years after they divorced.
He still lived with his sister. They had a suspicion his sister was the one he felt an intense loyalty to but they had no proof. They hoped JJ could extract a confession from him. They had to break him. He was their only hope.