Trial opens Tuesday for a prison parolee charged with slaughtering a couple and their 6-year-old boy in their Southern California home, leaving a baby girl unharmed near her mother's body for two days.

Opening statements were scheduled in the murder trial of 39-year-old Quang Van Quan of Houston, who is accused of tying up and stabbing to death a former prison acquaintance and his family in 2006, possibly over an $80,000 debt.

The man's baby daughter was found alive two days after the killings.

Quan was arrested July 12 in Houston and charged with three counts of murder during a robbery and burglary. If convicted of murder with special circumstances, he faces life in state prison without possibility of parole. He has been jailed without bail.

Quan is accused of killing Phuong Le, 30; Ngoc Lam, 25; and her 6-year-old son, Tommy Lam.

"The way these victims were murdered was pretty brutal" and might be considered torture even though Quan was not charged with that crime, Emami said.

The husband and wife were hog-tied and Le's spine was practically severed by the attack, she said.

Investigators discovered their bodies May 29, 2006, after a co-worker reported that Lam had missed work at a casino in San Bernardino County where she was a card dealer.

Prosecutors contend Quan and one or more other accomplices killed the couple and fled with family cell phones and a laptop.

The accomplices have not been identified, but the investigation continues, said Farrah Emami, a spokeswoman for the county district attorney's office.

The couple's 11-month-old daughter was left on the floor of the master bedroom where her mother was killed. She was wearing a soiled diaper and was severely dehydrated when police found her.

The girl's mother was found partially covered with a pillow. Her ankles and wrists were bound behind her back. She had been stabbed several times in the back and her throat was slashed, prosecutors said.

Le's body was found in an office bedroom. He was similarly bound, pajamas and underwear were tied around his head, and he had been stabbed several times in the head and neck, authorities said.

The couple's 6-year-old son, Tommy Lam, was found partially covered with a pillow in his bedroom. He had been stabbed in the back and head.

Investigators believe a dispute over money may have led to the killings. Quan has two 1990 convictions for robbery and assault with a deadly weapon. He and Le met at Avenal State Prison in Central California in the mid-1990s while both were serving time for unrelated robberies and the later tried to start a business together, authorities said.

Investigators found an IOU in the home from Le that indicated he owed Quan $80,000, prosecutors said.