A Marquette Heights resident, Dalton Lee Mattus, 35, has been sentenced to 57 months in prison followed by three years of supervised release. The sentence was handed down on March 5, 2025, after Mattus was found guilty of possessing a firearm as a felon, possessing a stolen firearm, and possessing an unregistered destructive device.
During the sentencing hearing before Senior U.S. District Judge Michael M. Mihm, it was revealed that Mattus had prior criminal convictions in Tazewell and Peoria Counties that prohibited him from owning firearms. In May 2024, he was stopped by Pekin Police Department officers while traveling as a passenger in a car. Officers seized a locked bag from the vehicle which contained a stolen Springfield Armory XD-S .45 caliber semiautomatic pistol and two unregistered destructive devices made from cardboard tubing, metal BBs, and chemical powder.
Further investigation led to a search of Mattus's residence where additional unregistered destructive devices were discovered along with materials for making more explosives. Authorities also confiscated 50 rounds of live ammunition and equipment used for assembling and disassembling firearms.
Judge Mihm remarked on the severity of the case, noting the homemade nature of the explosives intended to cause harm: “about as bad as it gets.”
Mattus was arrested by Pekin Police in May 2024 following these discoveries. A federal complaint was filed shortly thereafter with an indictment following in June 2024. He pled guilty in October 2024.
The statutory penalties for his offenses include up to 15 years’ imprisonment for possessing a firearm as a felon and up to ten years each for possessing a stolen firearm and an unregistered destructive device. Each charge carries up to three years of supervised release.
The investigation involved multiple agencies including the Peoria Area Federal Firearms Task Force—comprising agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives; Peoria Police Department; Peoria County Sheriff’s Department; Illinois Department of Corrections; Illinois State Police—as well as participation from Pekin Police Department and Tazewell County Sheriff’s Department.
This case is part of Project Safe Neighborhoods (PSN), aimed at reducing violent crime and gun violence through collaboration between law enforcement agencies and communities. The program emphasizes trust-building within communities, supporting violence prevention organizations, setting strategic enforcement priorities, and measuring outcomes.
