Harald Shipman has committed suicide in prison (so did Fred West). Here is a BBC profile. He had 15 (concurrent) life sentences for murder, but he is thought to have murdered more like 215 people.
LATER NOTE: I think the German TV news report I saw (ARD) got it wrong in saying ‘mehrere lebenslängliche Freiheitsstrafen’ (several terms of life imprisonment), because that sounds like the U.S. system of consecutive life sentences. Under the English system, the sentences are concurrent; the more there are, the less likely the defendant is to get out of prison early.