Once you are released from jail, get the guard's timecard from the Clown Store, and go to the Security Room at the museum. Look at the video surveillance tape and get a photo of the thief. Show it around at Downtown (everyone there will redirect you to the mimes). The thief is now at the All That Jazz Cafe, though if you look there first, he isn't there.
In Counterfeit Island you go and find the person who stole The Scream that's the painting that gets stolen at one point. Then you must find the criminal who stole it.
You need to get the key from the curator. This happens soon after you get arrested and you find out who stole the painting.
You can find out by looking at the security videos in the museum Security Room. You will need the time card from the night security guard, who is at the Clown Store.
he is at the music store after he steals the painting
you find a splattered painting and in the top right corner the painting is peeling and "the scream" painting is behind it
There is no key. Go upstairs to find the painting.
Peel of the painting in the house then you will be their
BoBo's Clown Store
Until the painting is stolen, you can't get into the cottage of the "Inspector" (presumably the Chief Inspector, who is actually the Black Widow). You will receive the key after you determine who stole the painting and chase the thief. The Commissioner and the security officer will help you with the video surveillance of the museum.
You don't have to find the Black Widow. She will find you. (Check the colorful painting.)
After the painting is stolen, that is what you have to find out. You need the timecard from the security guard (who is now in the Clown Store), and the security videos of the museum Security Office. Once you have a photo of the thief, show it to the mimes in Downtown, who will give you the clue to find and chase the crook.
You will receive a key to the Inspector's house, and find the stolen painting there. Then you will also find the Black Widow...