The Associated Press

MAYFIELD - A thief stole $21,000 worth of lithographs by the late pop artist Roy Lichtenstein from an insurance building, police said.

The framed lithographs - Bull Head I, Bull Head II and Bull Head III - were last seen Oct. 31 in a building at insurance company Progressive Corp.'s headquarters in this Cleveland suburb, police Sgt. Donald Smith said.

Police still had no suspects Friday and were puzzled by how the thief left the building unnoticed, possibly in daylight, carrying the framed 27-by-35-inch works of art. Each is valued at $7,000.

"It's sort of brazen to walk in, pick three pieces of art off the wall and possibly walk straight out the front door," Smith said.

The thief could have timed the heist to leave the building when no security was around, he said.

Police said no one has tried to sell the limited-edition works to Cleveland area art dealers.

Some of Progressive's 6,000 employees who had access to the building over the last two weeks are being interviewed, Smith said.