He hasn't been convicted of anything, so he is legally, under common usage in US and Britain, not a criminal, just a suspect avoiding investigation. The British have the strongest case against him, since he apparently violated the terms of his bail agreement while the British were deciding whether to honor the extradition request from Sweden. Sweden wants to question him on complaints from several women. The last remaining charge in Sweden is rape, the other complaints against him having expired under Swedish law's statute of limitations.
Ecuador's position is that he can stay in their embassy in London until they decide if he is really a criminal under Ecuadorian law, which may not extend to anything that happened in Sweden. Assange through his lawyers has said (or at least implied) that he does not fear the charges in Sweden, but is concerned that Sweden might extradite him to the USA, where he certainly has pissed off many individuals who have the power to do him serious harm.
It wouldn't be too difficult to construct a Tom Hanks-style movie drama where a popular anti-big-government hero is trapped by a weakness he cannot resist (sex) and then falls into the clutches of the forces he has been successfully opposing and exposing. In my script, there would be a lot of twists and turns by government officials who say one thing in public while enabling the victim's "escape" by their private actions. I read somewhere that if he can get to Iceland he will be free and clear. "Hey Julian," his lawyer tells him, "The good news is that we can get you out of any possibility of a life sentence in USA. The bad news is that you will have to live the rest of your life in Iceland."
I am still curious to know why LE called him a criminal - which if those diversions in his life was LE referring to?