The murder conviction came after a six week trial. For two decades there were no leads, no witnesses and no suspects.
Wong was raped and murdered in 1991. Her body was found in her Richmond District apartment. The case went cold for 17 years.
In October 2008 Otis Hughes, who had a long history of home burglaries, was released from state prison. Two months later, he was re-arrested and charged with the murder of Wong.
San Francisco District Attorney George Gascon explains why. He said, "As a condition of his release, he had to provide a DNA sample. And the DNA sample in 2008 matched the 1991 murder."
San Francisco Police homicide inspector Joe Toomey worked on cold cases, but has since retired. He told us, "We got a hit that it came back to a person by the name of Mr. Otis Hughes."
It took five more years before the case was adjudicated. It was mired in legal challenges in the appellate courts. Finally, on Monday, a jury convicted Hughes of Wong's murder.
Film producer Allie Light was Wong's friend. She told us, "I can't say I'm joyful because it'll never bring her back, but at least as of yesterday at five o'clock, there's a resolution."
Light was working with Wong on a documentary about mental illness called "Dialogues With Mad Women." Wong, a local activist, was profiled in that film.
In the movie, Wong said, "I was a member of a Marxism-Leninism organization. I had spent all of my adult life involved in radical politics."
Light finished the film after Wong's death. It went on to win a national Emmy Award. For more than two decades the unresolved death haunted Wong's family and friends.
"In this particular case, we have no witnesses. It was all the DNA," said Toomey.
Now the story and the film finally has an ending.
Hughes will be sentenced early next year. Gascon wants the judge to give him life without parole.