Medieval-style executions & gangs who cut out hearts... inside world's 'murder capital' after Brit lynched in street / Police hunt for man in connection with London murder - and urge public to not approach / Major update on 'violent' deaths of British couple as French cops can't rule out killer on loose / Citibank executive 'bludgeoned to death' in London flat as police hunt killer / Thames homicide: Neighbours say foul language, threats heard before man's death