Imprisonment for public protection

In England and Wales, the imprisonment for public protection (IPP; Welsh: carcharu er mwyn diogelu'r cyhoedd) sentence was a form of indeterminate sentence introduced by section 225 of the Criminal Justice Act 2003 (with effect from 2005) by the Home Secretary, David Blunkett, and abolished in 2012. It was intended to protect the public against criminals whose crimes were not serious enough to merit a normal life sentence but who were regarded as too dangerous to be released when the term of their original sentence had expired.

Source: Wikipedia — Imprisonment for public protection (CC BY-SA 4.0)