Updated at 9:22 a.m.
Before sunrise Tuesday morning, an 18 person FBI team along with Rogers County investigators journeyed to Oologah to investigate a tip on a 2013 cold case.
The multi-agency hunt for evidence came together after the Norman Police Department received a tip from an informant.
Rogers County Sheriff Scott Walton said, "The informant talked about two people of interest who are said to have shot and killed an individual, dismembered them with a chainsaw, and threw them in the lake."
The pond, he said, is on a residential property in Oologah, where search efforts were focused Tuesday morning.
While no names or identifiers, related to the people of interest or alleged victim, are being released at this time Walton did say: "We are talking with a person of interest who is cooperating."