The 5th... Who needs it anyway?

Apparently, you or I won't after this precedent is established.

Defence lawyers have indicated that the former neuroscience graduate might plead not guilty by reason of insanity. If he does, the judge has ruled he might have to submit to a "narcoanalytic interview" - including the use of what some have dubbed a "truth serum" - as part of the evaluation of his mental state. A narcoanalytic interview is a decades-old process in which patients are given drugs to lower their inhibition. The judge said Holmes could also be given a lie detector test as part of the evaluation.

You have a right not to self-incriminate. Seriously, is it even needed at this point?

On July 20, 2012, police arrested an unresisting Holmes next to his car behind the Century 16 theater, moments after the 2012 Aurora shooting, in which Holmes allegedly set off several gas or smoke canisters and then opened fire on the theater audience, killing 12 and wounding 58. The responding officers recovered several guns from inside the car and the theater. According to two federal authorities, Holmes had dyed his hair orange and had called himself "The Joker".[59] Although it should also be noted, that Holmes calling himself "The Joker," was later retracted [60] to news sources such as "Face The Nation," on the CBS News network, by police. Once apprehended, Holmes told the police that he had booby-trapped his apartment with explosive devices before heading to the theater.[13][61][62] Police later confirmed the presence of explosives in the apartment.[63]

What would be infinitely more telling is the prescription medications he was taking at the time. I'd venture that he was on some combination of ADHD and anti-depressant medications, many of which can have serious manic-depressive side effects.