Five large upside-down crosses spray-painted across the main entrance of the Cathedral of St. Paul greeted maintenance workers Saturday morning.

Sunday morning, the day after the well-publicized Rapture predicted by Harold Camping, three sets of empty clothes and shoes -- a man's, woman's and child's -- lay on the front steps.

The Rev. Joseph Johnson, rector of the cathedral, found humor in the clothing, but he didn't find the graffiti so funny.

"The amazing thing is that in a century standing on this hill, this is the first time we've had such an ugly incident," he said of the graffiti. "It's one of the jewels that we share, so it's sad that someone would cheapen it."

St. Paul police are investigating the graffiti as a possible "bias crime," said Sgt. Pete Crum, a department spokesman.

Johnson doesn't believe the graffiti and clothes are related. The white graffiti was spray-painted sometime overnight late Friday to early Saturday. It was removed Saturday morning with no damage to the wooden doors. There have been no arrests, with neither suspect descriptions nor surveillance footage of the incident.

The rector had a good chuckle over the clothes.

"Oh, that's funny," he said with a smile. They were laid out "as if a there was a family there that, boom, got transported."

Vandals spray-painted upside-down crosses on five of the cathedral's six main doors on Summit Avenue. The last time the cathedral was vandalized was in 1975, when a man with mental health issues lit a fire in the lower level, causing smoke damage to the main level, cathedral spokeswoman Carolyn Will said.

Crum said the motive for the graffiti is unclear, although Johnson acknowledged that talk of Saturday's Rapture could be a motive, as well as a simple prank or plain hostility toward the church.

"The spray paint is clearly hostile," Johnson said. "It's certainly very kind of in your face."

There's no evidence it's linked to weekend protests regarding the gay marriage legislation at the Capitol, Crum said, although that, among other motives, will be part of the investigation.

Will said that it does not appear linked to the protests and that the Rapture is a more likely factor.

News of the vandalism upset visitors to the cathedral, which is just outside downtown St. Paul.

"This is so devastating," said Theresa Galus-Gurien, an Atlanta resident who was visiting with her sisters and other relatives. "Hopefully they will learn from what they did and feel remorse."

Cathedral staff members are reviewing security procedures in light of the incident, Johnson said, declining to elaborate. Security is on the site.

The cathedral is open daily from 7 a.m. to 7 p.m., except for Saturday, when it closes at 9 p.m.

Chao Xiong • 612-270-4708