WEST CHESTER, Ohio (WKRC) - Butler County deputies and the FBI teamed up to arrest a suspected drug dealer and seize fentanyl. On Tuesday, the Butler County Undercover Regional Narcotics Taskforce searched an apartment in West Chester. They say they found 3.4 ounces of fentanyl during that search. With the help from the FBI, Sheriff Richard Jones said they arrested Louis Cooper. Cooper is charged with aggravated trafficking and possession of a controlled substance.