Authorities say they found a Batman mask and a drawing of a game involving a serial killer in the apartment of Colorado theater shooting defendant James Holmes.

James Holmes in court (KCNC TV)

The discoveries were revealed Wednesday during a pretrial hearing on whether evidence seized from Holmes' apartment can be introduced at his trial.

A Batman movie was showing at the suburban Denver theater where 12 people were killed and 70 others were wounded in the 2012 attack.

An FBI agent says the mask was found in Holmes' apartment by a bureau-led evidence team.

A police detective says the drawing was found in a spiral notebook inside a backpack in the apartment.

Holmes has pleaded not guilty by reason of insanity to multiple charges of murder and attempted murder.

(Copyright 2013 The Associated Press. All Rights Reserved)