A man pulled over in Jefferson Parish driving a van apparently outfitted for a sniper asked a federal magistrate Monday to suppress several seemingly ominous items seized during the May traffic stop, claiming authorities did not have a search warrant for the vehicle.

The evidence that Dominick Gullo wants to keep out of his upcoming trial includes an unregistered silencer, a loaded .22-caliber rifle with a scope and an 8-foot cannon fuse that law enforcement officials found inside the van.

Possession of the unregistered silencer formed the sole basis of the federal indictment handed up against Gullo in June. Gullo’s co-defendant, Joseph F. Gagliano, a passenger in the van, was charged with that and with being a felon in possession of a firearm.

A motion filed by defense attorney Patrick Hand Jr. claims the evidence, discovered “after approximately an hour of searching every nook and cranny” of the van, should be considered inadmissible because the warrantless search violated Gullo’s Fourth Amendment rights. In a phone interview, Hand said investigators did receive a search warrant for the vehicle the day after the traffic stop but had not obtained one when they began looking inside the 1998 Ford.

Hand requested an Aug. 21 hearing to argue his motion to suppress the evidence. That would delay the trial, now scheduled to begin Aug. 18.

Prosecutors had not yet responded to the motion late Tuesday, but Assistant U.S. Attorney William Quinlan filed a motion to postpone the trial “to allow the parties to complete discovery and plea negotiations.” He said the government “has turned over a number of discovery materials and has alerted defense counsel that some laboratory examinations have not been completed, so additional reports are anticipated.”

A spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, the agency investigating whether the sniper van had any intended targets, could not immediately say Tuesday whether authorities obtained a warrant for the search.

Jefferson Parish authorities, responding to an automatic license plate reader that flagged the van’s stolen plate, pulled over Gullo as he arrived at his East William David Parkway home May 7. Gullo, 72, had no documentation for the vehicle, which he claimed to have purchased earlier in the day for $300 at a nearby coffee shop.

Fearing the vehicle had been retrofitted for killing, authorities have been investigating whether any fatal shootings — planned or executed — can be linked to the vehicle or the rifle, which had been stashed under a carpet. Deputies found the silencer stowed in a side compartment and a length of cannon fuse — a wire capable of detonating an explosive device — under a sandbag behind the driver’s seat.

The vehicle had custom sliding windows that could function as gun ports, and two dining room chairs, whose legs had been sawed off, were stationed in the cargo area in a way that could provide a gunman a concealed vantage point. Authorities discovered the contents of the van as they were preparing to tow the vehicle from Gullo’s home.

Gagliano, 55, is a convicted felon who served federal prison time in the mid-1990s for racketeering. He is the son of Frank Gagliano Sr., who was widely considered an underboss of the Marcello crime family in New Orleans before his 2006 death.

Follow Jim Mustian on Twitter, @JimMustian.