l Claire Morris

Ms Morris died in a car crash in 1994 caused deliberately by her husband Malcolm Webster. After they had been married for only seven months, the former nurse drugged Claire, crashed their car near their home in Oldmeldrum in Aberdeenshire and set the vehicle on fire with Claire still inside.

He then moved to New Zealand where he was found guilty of trying to murder his second wife, Felicity Drumm, in another planned car crash in 1999.

Detectives started investigating Webster's past when one of Mrs Drumm's sisters contacted the police in 2006 to report her suspicions about him. In 2011, he was found guilty of murdering Claire to obtain life insurance money and was jailed for 30 years.

l Andrew Oates

Mr Oates was killed by his partner Sharon Hollinsworth, who involved her son and daughter in the murder plot. She hit Oates with a hammer at their home in Peterhead, Aberdeenshire and police also discovered the family had exchanged texts about weapons.

Hollinsworth, 44, admitted murder, conspiracy to murder and attempting to defeat the ends of justice and was told she must serve at least 11 years in prison. Her son Christopher, who admitted conspiracy to murder his father, was jailed for four years and two months. Natalie Hollinsworth, his half-sister, who admitted conspiracy to murder and attempting to defeat the ends of justice, was jailed for five years.