On Sunday night Derek Gallagher, 32, was shot at the wheel of his sports car outside his home in Sacriston, Co Durham. Police described Mr Gallagher, known as the Dealer, as a victim of a "delicately calculated and cold- blooded attack".
Mr Gallagher, who was unemployed and had a criminal record, lived in an isolated former pit village. He was taken to hospital in Durham but died during emergency surgery. A 9mm handgun is believed to have been used to kill him.
Detective Superintendent Tim Ryan said: "This was a deliberately targeted assassination, for whatever reason."
On Friday, Saul Soloman Nahome, 48, a jeweller, was shotoutside his house in Finchley, north London. "Solly" Nahome tried to flee his killer, who was riding a motorcycle, but the attacker caught up with him and shot him four times in the head.
Mr Nahome specialised in fraud and money laundering and was also a financial adviser to the notorious Adams family, which is said to control a crime empire worth pounds 100m. Police were trying to establish a motive for the killing.
Police sources said Mr Nahome was known to meet senior members of the Adams gang and had helped to hide pounds 25m of their drug money in property deals and offshore accounts.
Hatton Garden in the City, the centre of London's jewellery trade, has become a money laundering centre. Mr Nahome's shooting has sent shockwaves through the area, raising fears that a gangland war is about to break out.Reuse content