A Texas emergency medical services technician was arrested and charged Friday with possession of a destructive device.
Bryce Reed is scheduled to appear in federal court Friday in Waco, Texas.
Reed is part of West’s Emergency Medical Services and was one of the incident commanders during the deadly April 17 fertilizer plant explosion.
Texas law enforcement officials are now launching a criminal investigation into the explosion. Investigators have largely treated the West Fertilizer Co. blast that killed 14 as an industrial accident.
The Texas Department of Public Safety said in a Friday statement that the agency has instructed the Texas Rangers and the McLennan County Sheriff's Department to launch a criminal probe.
DPS Director Steven McCraw says in a statement he wants to ensure "no stone goes unturned" in the investigation.
There is no known connection between Reed and the explosion at this time.
The Associated Press contributed to this report.