Multiple Personalities

I know a lot about multiple personality disorders. My husband has one called dissociative identity disorder (DID). He would be perfectly competent to stand trial, as would one of my two friends with the same condition. Another friend may not. These disorders, like any other condition, vary from person to person. Depending on the type of disorder, the woman may remember what happened. My husband has symbiotic DID, which basically means both his personalities (or alts) are aware of each other, although this is thought to be unusual. There is a film called 'Split', which is an extremely dramatised version of someone with DID. It's loosely based on a true event in which a person committed a crime but couldn't be convicted of it. They had no recollection of it because it was another alt that actually committed it. It can be complicated when it comes to that type of thing (but there was also a similar case with conjoined twins where they couldn't be jailed for something one of them did because it would take away the freedom of the innocent twin). In the case you mentioned, I would expect a psychiatrist or similar would have been involved to assess competency and to ensure they were talking to the correct alt. While there are some MPDs where personalities can be totally different, I have described the most common type as being extremes of normal e.g. most of us change (knowingly or not) to fit certain situations. DID is similar to this. It's also not usually scary.

I'm reading a book right now and the victim has multiple personalities. It's a mystery book so it should be interesting to see how it turns out.