Detroit (CNN) -- Metal detectors belonging to the Secret Service that were on a stolen rental truck have been recovered, a law enforcement source said Monday.
The metal detectors, which were to have been used at a campaign event for Vice President Joe Biden, were found at an abandoned house in Detroit and in the U-Haul, left near Henry Ford Hospital, the source said.
Authorities want to question a man in connection with the theft of the U-Haul, found a day after it disappeared from its spot at the Westin Book Cadillac on Sunday.
Surveillance photos from security cameras at the hotel show a man in a green T-shirt and dark shorts near the truck before it was taken.
The stolen truck was found Monday, Secret Service spokesman Ed Donovan said.
The law enforcement official, who did not speak for attribution, said there were no weapons inside the vehicle.
Biden spoke at a downtown rally organized by the Michigan AFL-CIO.
CNN's Carol Cratty and Jonathan Helman contributed to this report