I just posted this a little while ago but I'll gladly do it again. My understanding is they sent him to Westville because that was the prison of choice for medical treatment.
The newly unsealed documents provide insight into what investigators found at the crime scene as well as their interactions with Richard Allen before and after his arrest.
www.huffpost.com
Prosecutors said that they had considered “involuntary medication” to treat Allen’s symptoms, but two psychiatrists and a psychologist had allegedly deemed it unnecessary, and they also felt it wasn’t necessary to move him to another facility with a psychiatric unit.