Authorities are still searching for one or more unknown accomplices.
Prosecutors said Quan and the accomplices murdered /*Phuong Le*/, 30, his 25-year-old wife /*Ngoc Lam*/ and their 6-year-old son, /*Tommy Lam*/.
They left the couple's 11-month-old baby girl alone in the home after the murders.
She was found conscious days later severely dehydrated, nonresponsive and lethargic when Garden Grove police officers made a welfare check at the home.
Concerned co-workers had called police when Lam failed to show up for work and the family did not return phone calls or answer the door for three days.
Prosecutors said the adult victims were found with their ankles and wrists bound behind their backs and stabbed several times in the neck and head.
Police also discovered an IOU note written by Le the month before indicating he owed Quan $80,000.
Quan was arrested nearly two weeks after the murders in /*Houston*/.
The identities of his accomplices are still unknown and anyone with information was asked to contact Supervising District Attorney Investigator Helen Moreno at (714) 347-8492.