GREENFIELD, Ind. -- Police on Friday were checking a missing mailman's background in hopes of finding clues as to why he disappeared this week.

John Jordan, 48, of Knightstown, vanished Wednesday after delivering mail to just one house on his Greenfield mail route.

"We don't know if we have (just) a missing person. We don't know if we have a homicide. We don't know if we have a suicide," Greenfield Police Chief Clarke Mercer told 6News' Rick Hightower.

Jordan's postal van was found in Greenfield on Wednesday after he didn't return to the local post office at the end of his shift. The vehicle was locked with mail, his cell phone and his wallet inside, the U.S. Postal Inspection Service said.

The USPIS said human blood was found outside the vehicle, but the service didn't say whether the blood had been matched to anyone.

Police said they were re-interviewing Jordan's friends and relatives and checking his credit card records, hoping to find something that would help them determine what happened to him.

A postal inspector said Friday that investigators did not know anything about a report that someone had been following Jordan on his mail route. Clarke said police have heard many false rumors about the case.

"Somebody said today, 'We understand you found his wallet out here at the pizza place on West Main Street with blood all over it.' Well ... that wallet was recovered in his truck," Clarke said.

Jordan's relatives handed pictures of him at a Greenfield church, hoping that someone might have seen him.

Greenfield's post office was closed Thursday and Friday because of the investigation, with workers doing their jobs from a Wal-Mart parking lot on Thursday. The post office is scheduled to reopen Saturday.

Jordan is about 5 feet 11 inches tall and weighs 170 pounds. He wears glasses and has a beard.

Police asked anyone with information about Jordan to call the U.S. Postal Inspection Service at 317-328-2530.