[SUP]President Maduro promised to track down those behind Mr Serra's murder[/SUP]
Venezuelan President Nicolas Maduro says a Colombian paramilitary group was behind the killing of a governing party lawmaker and his partner on 1 October.
Robert Serra and Maria Herrera were stabbed to death in Caracas.
Mr Maduro said Mr Serra's bodyguard had confessed to conspiring with a Colombian gang to kill the member of the National Assembly.
The president also said that there had been a series of attempts to kill other top socialist party officials.
Mr Maduro had previously blamed "ultra-right" opposition groups in Venezuela and in neighbouring Colombia for the murder.