Zilka, a 12-year veteran of the force, was issued a misdemeanor DUI ticket in the accident Sunday morning that caused the death of her 33-year-old passenger, Schauer.
RELATED: Joliet Officer Erin Zilka charged with DUI in crash that killed off-duty Berwyn Officer Charles Schauer
Both officers were off duty at the time when she crashed her Dodge Durango into the back of a box truck that had been involved in another drunk driving crash on I-55 near Plainfield.
The Illinois State Police recommended that she be charged with DUI and driving too fast for conditions, but the investigation continues.
The Will County prosecutor's office citing a potential conflict of interest in prosecuting the Joliet officer, so they have requested that a special prosecutor be appointed.
Zilka's attorney says his client's blood alcohol level was under the legal limit and that the stretch of road was so dark where the accident happened that Zilka was unable to see the crash as she approached it.
Illinois State Police said 42-year-old Rodrigo Marin of Plainfield was intoxicated and caused the initial crash with the box truck. According to state police, Marin lost control of his Nissan, crossed over the lane and struck the front left side of the box truck, which was in the right lane as it prepared to exit to Rte. 30.
State police said Marin fled on foot and was taken into a custody a short distance away. Neither he nor the box truck driver were injured.
Meanwhile, Officer Schauer will be laid to rest this weekend.