The three gangs are those led by Angoda Lokka, Makilangamuwe Sanjeewa and Kolonnawe Chamara.
Rodrigo was arrested along with seven of the gangsters during a raid by the STF at Henpitagedara in Divulapitiya on October 23.
A member of Makilangamuwe Sanjeewa’s gang was killed in the exchange of fire with the STF, while two others fled the scene.
Investigations revealed the gang had been there to seize unearthed treasure from a resident of the area.
Police seized 115 bullets, a bullet-proof vest, 68 grams of explosives, a sword and a knife in a subsequent search at Rodrigo’s home.
Later, his wife, an Indian national, too, was taken into custody.