"All political murder cases in the last 20 years, including those that had taken place in Kannur district, should be inquired by CBI," he told reporters here.
Venugopal was speaking after visiting the bereaved family members of Marxist rebel and Revolutionary Marxist Party (RMP) leader T P Chandrasekharan, who was hacked to death by unidentified assailants at nearby Vadakara on May 4 last.
He said the culprits in several political murders had escaped because the eyewitnesses were afraid to divulge details.
The culprits and all those behind the "brutal and heinous" murder of the RMP leader, who was expelled from CPI-M some years ago, would be brought before law, Venugopal said.
