The elaborate mission to recover a moon rock led NASA agents to one of the most down-to-earth places: a Denny's restaurant in Riverside County.

But at the end of the sting operation, agents were left holding a speck of lunar dust smaller than a grain of rice and a 74-year-old suspect who was terrified by armed officials.

Five months after NASA investigators and local agents swooped into the restaurant and hailed their operation as a cautionary tale for anyone trying to sell national treasure, no charges have been filed, NASA isn't talking and the case appears stalled.

The target, Joann Davis, a grandmother who says she was trying to raise money for her sick son, asserts the lunar material was rightfully hers, having been given to her space-engineer husband by Neil Armstrong in the 1970s.

“It's a very upsetting thing,” Ms.Davis told The Associated Press. “It's very detrimental, very humiliating, all of it a lie.”

The strange case centers on a speck of authenticated moon rock encased in an acrylic-looking dome that appears to be a paperweight. For years, NASA has gone after anyone selling lunar material gathered on the Apollo missions because it is considered government property, so cannot be sold for profit

Still, NASA has given hundreds of lunar samples to nations, states and high-profile individuals but only on the understanding they remain government property