There was some initial confusion in the twittersphere asking how James Holmes could face 12 counts of first degree murder when he (allegedly) killed 12 people. The answer is pretty simple: he is charged with both intentional homicide and with the lower intent level of malice, which the Colorado statute describes as follows:
universal malice manifesting extreme indifference to the value of human life generally, he knowingly engages in conduct which creates a grave risk of death to a person, or persons, other than himself, and thereby causes the death of another
I don't imagine that it will be impossible to prove that Holmes intended the murders, but the DA wants a second and easier path to conviction as well. What makes this statute a little different than some other jurisdictions is that the two different mens rea levels - purposefulness and malice manifesting extreme indifference - are both treated as first degree murder. In some jurisdictions, they are split apart and intentional murder is treated as more culpable.