The suspect in the Colorado theater massacre could enter his long-expected insanity plea, or the case could veer off on another tangent as his lawyers seek the strongest possible defense.

The judge has indicated he'll let James Holmes change his plea from not guilty to not guilty by reason of insanity at a hearing Tuesday.

But it's possible that Holmes' lawyers could ask the state Supreme Court to hear their arguments that state laws on the insanity plea and the death penalty are unconstitutional.

That could delay the case for a few days or longer, depending on whether the justices decide to consider the matter.

Holmes is charged with fatally shooting 12 people and injuring 70 in an attack at a suburban Denver movie theater in July.