Delano Wells, 50, of Trenton, has been charged in federal court in Dayton with making false statements on a federal firearms form.
Detective Jorge Del Rio was working as part of a DEA task force when he was shot in the face on Nov. 4 after entering a home. He died days later.
Nine kilograms of suspected fentanyl, six plastic tubs of marijuana and about $50,000 were found in the basement, according to a criminal complaint filed in federal court in Dayton.
Three guns were also recovered from the home – an AR-15-style rifle and two pistols, including the one that killed Del Rio, officials said.
The FN Five-seveN (a semi-automatic pistol that fires a 5.7 mm round) pistols were loaded with armor-piercing ammunition and equipped with laser sights, according to investigators. One of the pistols was found on the floor, and the other was being carried by a man in the basement, court documents say.
Dubbed a “cop killer" more than a decade ago by the Brady Campaign, an FN pistol was used in the 2009 Fort Hood shooting that left 13 people dead.
Del Rio may be the first police officer to have been killed with the gun in the U.S.
Investigators believe Del Rio bought all three guns, in addition to at least six others. The Bureau of Alcohol, Tobacco, Firearms and Explosives traced the purchases of the three guns to August and early September.
Wells told ATF agents he bought the guns in Middletown for a friend. Wells said the friend previously managed another gun store.
Wells said his friend would pay him an additional $20 to $30 in addition to the price of the gun, court documents say.
At least one of the FN pistols was purchased by Wells at Thompson’s Guns in Middletown.
The complaint states Wells told the ATF he thought his friend was trying to “avoid drawing attention to himself by purchasing so many firearms.”
On federal forms used to purchase the pistol, Wells claimed the pistol was being purchased for himself and not someone else. Anyone who purchases a firearm from a licensed dealer has to verify they are not purchasing the gun for someone else.
U.S. Attorney David DeVillers, who took over this month as head of the district that covers the southern half of Ohio, announced the charge against Wells in a news release Wednesday.
DeVillers said sentences can be significantly increased when guns bought by "straw purchasers" are used to commit crimes.
"The message we want to make loud and clear is that if you provide firearms to drug dealers and convicted felons you will be held responsible for their actions," DeVillers said in the release.
Three men face federal charges in Del Rio's death.
Nathan Goddard, Jr., 39, has been charged with intentionally killing a law enforcement officer.
Two others, Cahke Cortner, 39, and Lionel Combs III, 40, are charged with causing death through the use of a gun in relation to a drug-trafficking crime.
All three face the death penalty if convicted.
Related Video: Houston Chief Reports 5 Officers Injured in Drug Raid
One sister has DACA status, the other doesn't: Their lives are worlds apart
This article originally appeared on Cincinnati Enquirer: FN Five-SeveN pistol: 'Cop-killer' gun used to kill Ohio policeman