he took their side when they were reciting the FAMILY prair after Rocco died. He knew the FAMILY prair because he's in their family aka he is their father. he tried to kill them when he had no idea they were his kin and was released from jail by the Yakavetta family. no one tipped them off, they received a page on the Russian's pager that murphy took after they killed the russians. when conner called the page number the russians assumed it to be the Russian calling so he gave information about the meeting that night in the hotel room. THIS is when the brothers turned into vigilantes. they went after the Russians and they were their first targets ever. Contrary to what alot of people think they haven't always been vigilantes, they turn because the Russians were after them after that bar fight, and Rocco helped them turn as well.
Boondock Saints 2: All Saints Day is filming this summer, so prolly 2005 or 2006