In an unusual move, the governors of North Dakota and Minnesota appeared jointly Tuesday to offer their condolences about the disappearance of college student Dru Sjodin (search) and express their support for the investigation.

"This is something that has touched every North Dakotan," Gov. John Hoeven (search) said at the press conference. "Every one of us has a link to the Sjodin family at a time like this."

The 22-year-old University of North Dakota student disappeared Nov. 22 as she was leaving her job at a shopping mall. Police believe she was abducted.

"We're very proud of the cooperation and the collaboration that's been exhibited," said Gov. Tim Pawlenty (search) of Minnesota, where the man suspected of the crimes is from and was recently released from prison.

Hoeven said additional law enforcement would be provided to hunt for evidence all through the weekend now that "the nature of the search has changed."

The governors said they would send National Guard members and other state employees. North Dakota was to send 175 people; Minnesota had not committed a number.

The governors' appearance with police Tuesday came just after the Grand Forks sheriff surmised that the young woman was probably dead.

Grand Forks County Sheriff Dan Hill's sobering comments came as he revealed that a shoe belonging to Sjodin turned up near the Red Lake River (search), and a jackknife and blood matching her type were found in suspect Alfonso Rodriguez Jr.'s (search) car.

"I certainly hate to be discouraging to the family or anyone, but it looks to me now that it's more of a recovery mission than a rescue," said Hill, who confirmed the shoe discovery during an interview Tuesday with The Associated Press.

The shoe, a black Nine West loafer, was identified by a college roommate of Sjodin. It is the only piece of clothing recovered so far, Hill said.

Sjodin (pronounced sha DEEN) was last heard from Nov. 22, calling her boyfriend on a cell phone from the parking lot of a Grand Forks mall where she worked at a Victoria's Secret.

An affidavit unsealed later Tuesday had only one new piece of information: Rodriguez's account of his whereabouts at the time Sjodin disappeared. According to the affidavit, Rodriguez told police he was watching a movie, "Once Upon a Time in Mexico" at about 7 p.m. that night.

Police said the movie wasn't being shown at any theater near the mall that day. Fox News has learned of reports that authorities have video of Rodriguez in the same Grand Forks mall where Sjodin worked.

The preliminary DNA match would be the most significant break yet in the attempt by authorities to tie Rodriguez, a convicted rapist, to Sjodin's disappearance.

Hill said investigators tested blood from Rodriguez's maroon, four-door 2002 Mercury Sable against DNA taken from Sjodin's toothbrush. Hill described the blood in the car as a small amount.

Hill also confirmed a media report that the interior of Rodriguez's car and its trunk had been extensively cleaned before his arrest.

Rodriguez, 50, has been charged with Sjodin's kidnapping. He has said through his attorney that he is innocent but has stopped communicating with police.

"If he is the man who did this, we hope he'll give us information that will help us find Dru," the missing woman's brother, Sven Sjodin, said Tuesday on Fox News. "But at this point, he's not saying anything."

The Associated Press reported Monday that a knife was discovered in the trunk of Rodriguez's car, and later reported that a sheath found near Sjodin's car matched the knife.

Sjodin's father said Monday he was dismayed to find that police recovered a knife from Rodriguez's car. But given his criminal past, he said he was not surprised.

"You know what? It's probably true," Allan Sjodin said. "That's his modus operandi."

Rodriguez has a history of attempted kidnapping with adult women, and has used a weapon in at least one assault. Rodriguez was released from a Minnesota prison in May after serving 23 years for an attempted abduction in 1979.

Fox News' Carol McKinley, Catherine Donaldson-Evans and The Associated Press contributed to this report.