Lambert was last seen in Palm Springs, California on November 30, 2008. A friend got a voice mail message from him on December 4, asking for a return call. The friend called back but wasn't able to reach Lambert. He has never been heard from again. His friend reported him missing on December 7. On December 14, police checked his residence in the 300 block of Camino Norte. The mailbox was full and Lambert and his car were gone. His vehicle is a silver 2004 Mercedes Benz with license plates numbered 5ZWZ335.

Lambert was having personal problems at the time of his disappearance. In 2007, he separated from his lover of ten years. Neighbors reported disturbances at their home and the lover requested a restraining order. Lambert's lover died in November 2007. Lambert's friends stated he was lonely and looking for a new partner. A former art dealer, he was prominent in Palm Springs society.

In March 2009, police arrested Kaushal Niroula and David Replogle and charged them with fraud and other offenses. Two other suspects, Russell Herbert Manning and Daniel Carlos Garcia, faced the same charges but remained at large. Garcia was apprehended a short time later, but Manning remains a fugitive and is believed to be in Mexico. Photos of Niroula, Replogle and Garcia are posted below this case summary. Authorities stated the men forged power of attorney papers, removed hundreds of thousands of dollars from Lambert's bank accounts, looted his home of art and valuables, and tried to sell the house for about one-third of its market value after Lambert went missing. The suspects had all of Lambert's identification and credit cards, and keys to his home and vehicles. Investigators believe the men were part of an identity theft team and may have victimized many people. Niroula has a significant arrest record for similar crimes. He is originally from Nepal and moved to the United States to attend college. He often claimed to be a member of the Nepalese royal family. Garcia admitted he knew Niroula and Lambert and was sometime lovers with both of them, but denies that he introduced the two men to each other or that he was in any way involved in Lambert's disappearance or knows what happened to him. He admitted he used Lambert's debit card after his disappearance to withdraw thousands of dollars from the missing man's account, but claims Lambert gave him the card and permission to use it at will.

Later that month, Niroula, Replogle, Garcia and Manning were additionally charged with first-degree murder. Garcia had been apprehended by then, but Manning was still a fugitive. A few days later, Miguel Adolfo DeLeon Bustamante was also charged with murder. He had initially been charged with burglary after police caught him red-handed stealing items from Lambert's house. In July 2009, a sixth suspect, Craig Milan Anthony McCarthy, was also arrested and charged with murder. Prosecutors may seek the death penalty against the defendants, as they believe the murder was committed for the purpose of financial gain. They are all awaiting trial.

Foul play is suspected in Lambert's disappearance due to the circumstances involved. Authorities believe he was stabbed to death during a burglary on December 6. He has never been located.

Left: Daniel Carlos Garcia;
Center: Kaushal Niroula;
Right: Daniel Replogle