Utah police were searching Thursday night for a man who strode into the state Capitol and placed a wreath and a cardboard box containing an unloaded rifle on the floor before leaving the building.

The Salt Lake City building was evacuated shortly after Capitol security officers watching surveillance cameras spotted the man leaving the package Thursday afternoon, state Highway Patrol Trooper Lawrence Hopper said.

The man appeared to be in his mid-20s and was wearing a dark suit and tie. After entering the building, he walked to the center of the main floor underneath the building rotunda and placed the package on the floor with the wreath on top, Hopper said.

He knelt next to the package for a moment and then got up and left the building. He drove off in a white SUV he had parked outside.

Hopper said Utah Highway Patrol troopers, who provide security for the Capitol, did not reach the man before he left.

The building was evacuated immediately after, but Hopper did not have details about how many people were there at the time. Gov. Gary Herbert was not in the building.

A bomb squad inspected the package and determined a few hours later that it wasn't an explosive.

The rifle was a semiautomatic rifle but Hopper did not have details about it.

The box was oblong and triangular and had a note written on it, Hopper said.

Citing the ongoing investigation, he declined to disclose what the note said or whether officials consider it a threat.

Hopper said they have a person of interest in the case who may help them understand the situation but Hopper wouldn't call the person a suspect.

While Utah law allows someone to carry a gun into the Capitol, Hopper didn't know if the man's actions would be considered a crime. He said prosecutors would make that call.

He declined to say whether officials know what the man's motive may have been but said no one spoke to him for the few minutes he was in the Capitol.

"It's bizarre," Hopper said.

He said officials believe it was an isolated incident and there is no threat to public safety.