Why didn't they blame all the murders that Harvey Dent committed on Joker? [duplicate]

Question

Today's question brought to you courtesy of awesome folks at "Honest Trailers" youtube series. Their "The Dark Knight" video made a point I never could figure out from Nolan's movie:

• They had several people murdered by Harvey once he became two-face
• If that fact became public, all the criminals would be released. That makes sense.
• So, they needed a patsy to blame for the murders instead of Harvey, to keep his reputation all white-knightey.
• Since they had nobody else to pin the murders on, Batman took the fall.

...

Wait WHAT????

They DID have someone else to pin the murders on! A psychopathic murderer! Who was at the moment conveniently known to everyone in Gotham as a criminal. Joker!

So, the question is, WHY didn't they pin the Harvey Dent's murders on Joker?

I'm looking for official explanation - from a movie; or DVD commentary; or interview with Nolan or someone else involved with the script.

Answer 1

I've got nothing official, but I did have 30 seconds spare to think it through.

In short: wouldn't work.

The point was to preserve Dent's public image as an incorruptible hero. So when you pin the murders on someone else, you need the public to accept it, and not have cause or opportunity to reconsider in the near future.

The Joker had, at that point, been apprehended and arrested. It's fairly likely he'll get his day in court (unless they just shove him in Guantanamo).

Someone with his intelligence and sense of showmanship could have a field day exposing false accusations like that - especially as he visited Dent in hospital to set him off on his murderous rampage in the first place. Even if the Joker ended up convicted of Dent's crimes, he'd relish the opportunity to tear down Harvey's white knight personna in the eyes of Gotham's citizens. It seems likely that he'd be able to sow enough doubt in the public's mind to prevent Dent from being an effective inspiration any more.

Whereas if he's not accused of Dent's crimes, the question doesn't come up in court. He could still try to bring it up, but that'd be much more difficult if it's not relevant to the case, and less likely to attract public attention.

It's much safer to blame Batman, a figure of mystery who's willing to take the fall, and is just about to disappear.