Wu Chen, 45, was arrested in Miami, Florida, just before 4 p.m. when a license plate reader flagged the vehicle he was driving, the Oklahoma State Bureau of Investigation said in a statement.A spokesman for the Oklahoma Bureau of Narcotics and Dangerous Drugs said Tuesday that the agency was investigating whether an active medical marijuana license obtained by the grow operation was valid.The property, described in the listing as 10 acres with 5,000 square feet of grow space and 50 temporary greenhouses, or hoop houses, was put on the market in May for $999,999.A neighbor, Brandon Walker, said the property used to be a dairy farm but was sold in recent years to an investment company, which sold the land again before it was converted to a grow operation.While the status of the grow operation where the quadruple homicide occurred remains unclear, law enforcement officials have reported a rise in black market operators using suspected human trafficking victims, including Chinese nationals, to grow and trim marijuana sold in legal dispensaries."