Walter Evans, who led the task force assembled to probe the shootings.

CNN: Police probe possible racial motive in Tulsa killings

The probe was not conducted by the Justice Department's campaign finance task force which has prosecuted similar conduit campaign schemes by backers of Democratic candidates.

CNN: By Terry Frieden/

But authorities have assembled a task force of about 25 investigators to assist in the probe, including city homicide detectives, the U.S. Marshals Service and the Federal Bureau of Investigation.

WSJ: Federal Authorities Join Probe of Tulsa Shootings