HAMMOND – A 22-year-old Gary man has been sentenced to 18 months in federal prison after police discovered he was carrying a firearm equipped with an illegal machinegun conversion device.

Cornelius Maurion Holmes, 22, of Gary, was sentenced October 28, 2026, by U.S. District Court Judge Gretchen S. Lund after pleading guilty to unlawful possession of an unregistered machinegun, according to U.S. Attorney Adam L. Mildred.

In addition to his prison sentence, Holmes will serve one year of supervised release.

According to federal court documents, the case began April 13, 2025, when Gary Police officers responded to a 911 call reporting two suspicious males walking in the street while carrying firearms.

Responding officers located Holmes and a juvenile walking in the middle of the roadway, matching the caller’s description. Officers noticed a firearm tucked into Holmes’ waistband and moved to secure the weapon for officer safety.

As officers lifted Holmes’ shirt, they immediately recognized a machinegun conversion device attached to the firearm. The device converted the weapon into a machinegun under federal law. Authorities determined the weapon was not registered to Holmes.

Machinegun conversion devices, commonly referred to as “switches,” allow certain semiautomatic firearms to fire automatically, significantly increasing their potential rate of fire. Federal law classifies firearms equipped with these devices as machineguns.

U.S. Attorney Mildred emphasized the dangers associated with these devices and warned that federal prosecutors will continue targeting individuals who possess or distribute them.

“These illegal machinegun conversion parts pose a significant threat to our neighborhoods and the brave law enforcement officers who work tirelessly to protect them,” Mildred said.

Mildred added that prosecuting individuals involved in the possession, manufacturing, or distribution of illegal conversion devices remains a priority for federal law enforcement.

The investigation was conducted by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), with assistance from the Gary Police Department.

Assistant U.S. Attorney Michael J. Toth prosecuted the case.