The man charged with killing 12 people during the Colorado cinema massacre in July (12) has reportedly attempted suicide behind bars.

James Holmes' latest hearing on Thursday (15Nov12) was postponed after he allegedly rammed his head against a wall at Denver's Arapahoe County jail, where he has been detained since 20 July (12) - the day Holmes reportedly opened fire at a screening of The Dark Knight Rises in an Aurora theatre.

He faces 166 counts of murder, attempted murder and other charges tied to the shooting spree.

The hearing will now take place on 10 December (12).