DAYTON, Ohio (WDTN) — The man accused of killing four in Butler Township in August has pleaded not guilty by reason of insanity.

According to court documents, 39-year-old Stephen Marlow could face the death penalty after police say he killed four people on a Butler Township Street, resulting in 12 counts of aggravated murder as well as several counts of aggravated burglary and one count each of having weapons while under a disability and tampering with evidence.

Marlow’s defense has submitted a motion stating that Marlow pleads not guilty by reason of insanity.

Court documents state that, because of this plea, Marlow must complete a competency evaluation to see if he is capable of standing trial. According to the document, a defendant is defined as incompetent if they are “incapable of understanding the nature and objective of the proceedings against the defendant or assisting in the defendant’s defense.”

After this evaluation is complete, the defense states that Marlow can then make a claim of Serious Mental Illness (SMI) at the time of the murders and complete another mental evaluation.

If the SMI claim is deemed to be valid, Marlow will be exempt from receiving the death penalty upon conviction, the defense said.