This week we learned that a series of artworks created by the Kray twins were set to fetch £15,000 at auction.
Artworks created by famous criminals are big business, with entire websites devoted to selling off everything and anything created by gangsters, serial killers or famous shooters.
The first question posed by work like this is whether, if it wasn't for their notoriety as criminals, anyone would attach any value to the pieces at all.
The Krays' at least demonstrate a degree of artistic skill in their colourful landscapes and abstract portraits, but as the gallery below confirms, not all killers who decide to pick up a paint brush are any good in a technical sense.
The second, altogether more intriguing question is whether viewers can ascertain some insight into the criminal mind by studying what their subconscious prompted them to paint or draw.
We all enjoy indulging in some cod psychology from time to time, and never more so when confronted with people capable of inexplicable crimes and violence.
Does John Wayne Gacy's clown paintings reveal something about his inner sickness? Should Richard Ramirez's cartoon devils be read as self-portraits? Or is all of that simply us projecting sanity onto an insane mind?
The following artworks by famous killers and criminals shouldn't be celebrated any more than their appalling crimes should ever be excused.
What they do raise, however, is some interesting questions about how we view art and creativity in relation to personality and criminality.
Take a look at the gallery below, and let us know how you feel about them.