Three of the four suspects charged in connection with a brazen heist of gold and gems from a state museum in the Sierra foothills have pleaded not guilty.

The Merced Sun Star reports that during their arraignment Monday, 43-year-old Matthew Campbell, 41-year-old Jonathan Matis and 40-year-old Edward Rushing III pleaded not guilty to robbery and other charges.

The fourth man charged, 42-year-old Christopher Scott Sheffield, was not represented by an attorney, so he did not enter a plea. He was ordered to return to court Tuesday.

Prosecutors say during the Sept. 28 robbery of the California State Mining and Mineral Museum in Mariposa the four men made off with $1.3 million worth of gold, gems and artifacts.

Investigators say some of the stolen loot has been recovered, but have not said how much.

All four suspects are being held on $1 million bail.