Roadkill - [s4e23]

: Penelope Garcia helps the team by tracking the specific modifications made to the Unsub’s vehicle, which was customized with hand controls to allow him to drive despite his paralysis. Character Highlights

: This episode marks one of the early cases after Jennifer "JJ" Jareau returns from her maternity leave.

: Revealed to be Mason Weaver , a man suffering from severe emotional trauma and a physical disability (paralysis from the waist down) caused by a car accident. [S4E23] Roadkill

that may have inspired this "vehicular heat" storyline.

The episode follows the Behavioral Analysis Unit (BAU) as they travel to , to investigate a series of vehicular homicides. The "Unsub" (unknown subject) uses a modified, heavy-duty truck as a weapon to run victims off the road or crush them. Key Plot Elements : Penelope Garcia helps the team by tracking

: The killer uses a specific stretch of highway known to locals as "Suicide 7" because of its dangerous, winding nature.

is the 23rd episode of the fourth season of the crime procedural series Criminal Minds , which originally aired on May 6, 2009 . that may have inspired this "vehicular heat" storyline

: Weaver targets people he believes are irresponsible drivers, acting out a vigilante fantasy to "punish" those who make the roads unsafe, mirroring the accident that ruined his own life.