Detroit man built up arsenal, spoke fondly of explosives, feds say

After federal agents arrested a 29-year-old Detroit man on explosives charges, a search of his house turned up “an arsenal of weapons, ammunition, tactical gear and tactical training materials,” according to charging documents filed Monday by the Justice Department.

Sebastian Gregerson, who goes by Abdurrahman Bin Mikaayl, has been charged with possession of an unregistered destructive device and unlicensed receipt of explosive materials. The bust followed an undercover operation that revealed Gregerson had been collecting the materials for the past 16 months.

“In my training and experience, and that of other agents upon whose expertise I am also relying, the purchase of training versions of these weapons makes it unlikely that the weapons were purchased for recreational use, such as hunting,” Ryan Schanberger, Special Agent with the Federal Bureau of Investigation, wrote in the complaint.

Items confiscated included firearms like an AK-47 and a Kel-Tec Sub 2000 9mm; 700 rounds of 7.62 ammo; a dozen 40-round AK-47 magazines; seven fixed-blade knives “of significant length,” two balaclava ski masks; holsters and a tactical vest; commercial grade road spikes and multiple training guns and dummy rounds.

The FBI launched an undercover investigation in April after a confidential informant told authorities Gregerson possessed grenades and bazookas. The undercover agent, on multiple occasions, spoke with Gergerson about grenades, explosives, and he had even discussed his plans to carry out an attack on a building.

During the course of the investigation, Gergerson told undercover agents how to make explosives using shells of smoke grenades and expressed a desire for heavier explosives like fragmentation grenades and claymore mines, which he called “a magical piece of equipment.”

At one point, Gregerson invited the undercover agent to his home where he showed the agent items similar to the ones that were later confiscated. He referred to the items — like a tactical vest loaded with ammo and mags — “game day gear” and said, “I don’t play around.”

Some time later, the undercover agent arranged for Gregerson to buy five M67 fragmentation grenades from another undercover agent. They agreed to exchange the M67s for a Beretta 9mm pistol. On July 31, Gregerson and the first agent met with the source at a gas station and once the purchase was completed, federal agents moved in and arrested Gregerson.

Gregerson appeared in a Detroit federal court this week. If convicted, Gregerson could face up to 10 years in prison.