Reading that poor woman's story, I'd say that -
1) "Friends and family were shocked to discover that the killer had a history of violence against women, including repeated harassment, threats and the kidnapping at knifepoint of one of his other ex-girlfriends."
2) "Ms Wood was initially charmed by Appleton’s persona after meeting him online, but his violent side soon surfaced and he subjected her to a string of sexual assaults."
3) "Ms Wood had first called police in October 2008 after he damaged her front door, threatened her with an iron and threatened to kill her."
and
4) "After they split he strangled her and set on fire in Salford in February 2009."
- maybe locking up men like that for a decent amount of time and making sure they get proper help with rehabilitation, is a better idea.