Celerino Castillo (born 1949) is a former agent for the United States Drug Enforcement Administration (DEA).
[1] Castillo was a detective sergeant with a Texas Police Department from 1974 until 1979, and graduated from the University of Texas–Pan American in 1976 with a BS in Criminal Justice.
Since 1997, he has been accepted as an expert witness in federal courts on outrageous government conduct, informants, and racial profiling.
In 2008 (three years before Operation Fast and Furious became publicly known), Castillo told reporter Bill Conroy that agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) were participating in the smuggling of high powered weapons into Mexico.
It was later revealed that his attorney was, at the time of his plea, suspended by the State Bar of Texas for misapplying clients' funds.