Body discovery could bolster San Pablo double-murder case - but where is other victim?

SAN PABLO, Calif. - The discovery of one of two bodies in a San Pablo double-murder investigation could change the trajectory of the case, but the location of the remains of the other victims isn't yet known.

"This is a big development in this case," said Peggy Chou, San Pablo police spokeswoman, referring to confirmation that the remains of Que Thi Tran, 74, had been positively identified.

Authorities say Tran's son-in-law, Phuc Vo, 41, killed her and that he also killed his wife, Tho Ly, 40. But Ly's body hasn't been found.

Chou said Vo was already being prosecuted in both killings.

"The suspect was previously charged for two counts of murder without the recovery of either victim," Chou said.

Back in September, an unidentified woman's body in undergarments was found in the Oakland Estuary. But it wasn't until March that DNA testing confirmed her identity.

"Detectives received that notification and confirmation that the DNA evidence was a match," Chou said.

Authorities believe Vo killed both victims in the family's home in San Pablo earlier in September, then tried to cover it up by reporting them missing.

SEE ALSO: San Pablo man reports wife and mother-in-law missing, now charged with murdering them

KTVU has learned San Pablo police believe Vo then took the bodies with him on a small boat that left the Encinal Boat Ramp in Alameda. Sources say police believe he dumped both bodies in the water.

But so far, his wife's body has not surfaced.

"At this time, her body and her location remains unconfirmed," Chou said.

But the discovery of his mother-in-law's body strengthens the case somewhat against Vo. KTVU has confirmed with the Contra Costa County district attorney's office the recovery of Tran's remains won't change its decision not to seek the death penalty. If convicted, Vo could face life in prison without parole.

"Now that they've found the body, though, this is a game-changer," said KTVU legal analyst Michael Cardoza.

At the same time, Cardoza said the DA still has to confirm the cause of death and prove that it was Vo, and not some random stranger, who killed at least the mother-in-law.

"They've got to be able to make that connection. They could say it was blunt force trauma. Somebody hit her in the head - that's what killed her. Or it was asphxyiation. Someone strangled her. Doesn't mean it was him," Cardoza said.

Henry Lee is a KTVU crime reporter. E-mail Henry at Henry.Lee@fox.com and follow him on Twitter @henrykleeKTVU and www.facebook.com/henrykleefan