RICHMOND -- A Contra Costa County judge Wednesday ruled that there is enough evidence to bring a former Pinole man to trial on murder charges in the 1999 killing of his son's mother.

Judge Patricia Scanlon, however, rejected a special circumstance allegation that a murder was committed for financial gain, which would have made computer engineer Raymond Wong, 41, eligible for a death penalty prosecution.

Prosecutors believe Wong fatally shot his 21-year-old girlfriend, Alice Sin, in the Nevada desert on Nov. 21, 1999 -- a week before their son's first birthday -- to collect on a $2 million insurance policy. Prosecutors think Wong was further motivated to kill by his relationship with another woman with whom he had just fathered another child, and because he believed Sin was pregnant again.

Pinole police long suspected Wong killed the Diablo Valley College student but could not convince the District Attorney's Office to charge him until late 2011.

At Wong's preliminary hearing Wednesday, Scanlon said she did not see evidence that Wong was behind the insurance policy that Sin purchased a month before Wong reported her missing on Nov. 22, 1999.

Prosecutor Mary Knox said that despite Scanlon's order, the District Attorney's Office has the option of adding special circumstances to Wong's charging document at his arraignment March 11.

Sin's body, shot four times and mutilated by wild animals, was found by a badger's nest in Churchill County, Nev., on Jan. 24, 1999. Stuffed in her bra was Monopoly money marked with "NWO" and "ZOG," acronyms associated with the white supremacy movement.

Detectives testified Wednesday that Wong researched the white supremacy movement on his computer shortly before Sin's death. After her death, he allegedly sent the Contra Costa Times and other Bay Area news organizations a poorly spelled email in which a fake Aryan organization took credit for Sin's murder.

Detectives testified that Wong and his other girlfriend, Jessica Tang, crafted an alibi for their whereabouts on Nov. 21, 1999, over instant message. In another email recovered from one of Wong's computers, he allegedly wrote Tang: "I would have killed her a long time ago, the only thing standing in the way was you. The more you harassed her, the harder it was for me to do."

Tang moved in with Wong less than a week after Sin disappeared, a detective said. When police searched the home on Nov. 24, 1999, they found all of Sin's clothes in garbage bags. During a later search, a letter to Sin regarding her insurance policy was found open on Wong's bedroom night stand.

Wong was the beneficiary of the policy, but he couldn't collect because it was suspended over missing medical records. He was convicted of possessing child pornography for images found on his computers by the Pinole detectives.

He had an active arrest warrant for failing to keep up with his sex offender registration when he moved to China in 2009. He was arrested at San Francisco International Airport in December 2011 upon trying to sneak back into the country with a fake passport, according to the detectives, and charged with killing Sin a few days later.

Wong is being jailed without bail.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.