SAN DIEGO -- A City Heights man accused of sexually assaulting and killing an Orange County man in San Diego last year and sexually assaulting a second young man this year pleaded not guilty Tuesday to murder and sodomy charges that could lead to the death penalty.

Philong Huynh, 39, was arrested last Thursday and charged with murdering and sodomizing 23-year-old Dane Williams of Huntington Beach.

The defendant also faces a special circumstance allegation of sodomy, which makes him eligible for the death penalty if convicted of killing Williams, who had come to San Diego to work a convention for a Costa Mesa-based skate and surfwear clothing company.

The intern disappeared after leaving the Hard Rock Cafe in the Gaslamp Quarter in the early morning hours of Jan. 26, 2008. Williams was intoxicated and was seen falling to the ground on all fours when he left the club, said prosecutor Gretchen Means.

The victim's body was found three days later in a City Heights alley one block from where Huynh lived, the prosecutor said.

Williams' body was wrapped in a blanket and he was wearing a cap, neither of which belonged to him, Means said. The victim's underwear was missing, and DNA evidence was found at the scene, the prosecutor said.

The DNA evidence was uploaded into a criminal database, but the suspect remained unidentified until four months ago, when a second young man came forward and alleged he had been sexually assaulted by the defendant, Means said.

The second man, whose name was withheld, said he met the defendant in the Gaslamp and the two ended up drinking and going to the beach. After telling Huynh he had a headache, he was given two pills he was told were Tylenol, then woke up without his underwear in the defendant's bed the next morning, the prosecutor said.

The man went to a doctor and was diagnosed with benzodiazepine intoxication and had visible signs of sexual assault consistent with sodomy, the prosecutor said.

Benzodiazepine is a central nervous system depressant, Means said.

The DNA evidence taken from the second alleged victim was matched to the defendant through DNA testing, and he was then linked to the Williams killing, Means said.

During a search of the defendant's home, pharmaceuticals were found, including a prescription for benzodiazepine in his name that was filled in January 2008 -- the same month Williams was assaulted and found dead, Means said.

In asking for no bail, the prosecutor told Judge Polly Shamoon that Huynh had family ties to Vietnam.

The judge scheduled a status conference for next Tuesday, a readiness conference for Sept. 25 and a preliminary hearing for Sept. 29.

District Attorney Bonnie Dumanis will decide later in the case whether the defendant will face the death penalty or life in prison without parole should he be convicted.