An investigator who says James Holmes' computer was used for an internet search on the words "rational insanity" has been approved to testify at Holmes' trial in the Colorado theater shootings.

The judge ruled Friday that Aurora Police Detective Michael Leiker (LY'-kur) can testify about his examination of Holmes' computers and electronics.

Leiker testified during an October hearing that he found evidence of the "rational insanity" search. He didn't say if he knew who did the search or when it was done.

Holmes pleaded not guilty by reason of insanity to charges of killing 12 people and injuring 70 during the 2012 attack. His trial is scheduled to start in October.

Evidence about Holmes' sanity will be crucial, but prosecutors haven't indicated whether Leiker's testimony will be part of their case.