ST. LUCIE COUNTY − A 22-year-old man accused of having devices to convert a semi-automatic pistol to fire fully automatically was arrested after law enforcement officials investigated a homicide in Stuart, according to recently-released records.

Derick Marvin Moulton, of the 1100 block of Southwest Hogan Street in Port St. Lucie, was arrested May 26 on a felony weapons-related charge. He is jailed in St. Lucie County.

Moulton’s arrest comes after Stuart police investigated the Nov. 24, 2022, fatal shooting of Mattie Lee Jones, 74, in East Stuart.

Recovered in the homicide case was a Glock pistol that investigators said had been modified with an “auto sear” to fire in a fully-automatic mode.

Typical Glock pistols are semi-automatic, firing one shot with each pull of the trigger. Fully automatic weapons, known as machine guns, can fire continuously as long as the trigger is pulled.

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The pistol was seized during a search of the home of Lonnie Bee Smalls III, 19, who faces charges including first degree murder with a firearm and discharging a machine gun in the Jones case.

Police found communication between Smalls and Moulton on Smalls’ cell phone, records show.

The communication involves Smalls trying to get an auto sear for a Glock pistol, according to records.

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Smalls wanted to trade an auto sear he’d previously gotten from Moulton because that sear would not fit his Glock.

Moulton shared a number of pictures of auto sears, and investigators report his “prints were identified in the pictures where he’s holding the auto sears,” records show.

There are two court dates later this month in the Smalls case.

Moulton has a separate St. Lucie County criminal case stemming from a 2022 arrest. That incident includes charges related to a weapon and marijuana after a traffic stop made by St. Lucie County sheriff’s investigators.

Will Greenlee is a breaking news reporter for TCPalm. Follow Will on Twitter @OffTheBeatTweet or reach him by phone at 772-267-7926. E-mail him at will.greenlee@tcpalm.com

This article originally appeared on Treasure Coast Newspapers: Man accused of having full-auto pistol conversion devices