(ARAPHAHOE, Colo.) -- The prosecution seeking the death penalty against James Holmes in the Aurora theater shooting case want to see what he's been doing in jail so that they can possibly use it against him during the penalty phase of trial if he is found guilty by a jury.
In a new notice filed Friday in Arapahoe District Court, District Attorney George Brauchler made a list of evidence he wants to see in order to establish a capital murder case, including "any video or audio recording of the defendant and/or any person he interacts with while incarcerated."
Former Colorado prosecutor Bob Grant says asking for jailhouse recordings is an excellent way to catch an inmate off-guard. "Every jail phone has big sign right there on the wall and the prisoners all sign a document that 'This phone is monitored' and it doesn't make a darn bit of difference. They say the most incriminating stuff," said Grant, a former district attorney for Adams County.
Grant, the last district attorney to successfully prosecute a death penalty case in Colorado, added, "I don't doubt that in some of those recordings the prosecutor is looking for something to establish state of mind. If he's (Holmes) making sense like a common man would make, then it would help them to disprove insanity."
There were 74 types of evidence requested in the motion, including cell site data from Holmes' cellular phone, 911 calls "related to disturbance complaints" the day before and of the murders, and spent shell casings collected from the Byers Canyon Rifle Range.
It's the first time law enforcement has publicly mentioned that the shooter may have used the range for target practice.
The penalty phase may be necessary because on April 1, Brauchler announced that he would seek the death penalty against Holmes.
He is charged with 166 counts in the shootings at the Aurora Cinemark theater on July 20 which left 12 people dead, including an 8-year-old girl. Another 70 people were injured.
Holmes' trial is scheduled to begin in February 2014.
Copyright 2013 ABC News Radio