LOS ANGELES (CNS) - Relatives of four people killed outside a Northridge boarding home sued the Los Angeles County District Attorney's Office and Probation Department today, claiming the man suspected in the killings was improperly supervised after his release from prison and should have been behind bars when the shootings occurred.

Ka Pasasouk is facing a possible death sentence for the Dec. 2, 2012, killings of Amanda Ghossein, 24, of Monterey Park; Jennifer Kim, 26, of Montebello; Robert Calabia, 34, of Los Angeles; and Teofilo Navales, 49, of Castaic.

Officials from the District Attorney's Office and Probation Department could not be reached after business hours for comment on the lawsuit.

In their Los Angeles Superior Court lawsuit, relatives of all four  victims contend that the county Probation Department failed to properly  supervise Pasasouk following his release from prison in January 2012. He was being overseen by the county instead of state parole officials under the terms of the state's prison-realignment program as outlined in Assembly Bill 109.

“The county failed to classify and identify him as a highly dangerous felon and subject him to `strict' supervision,” according to the lawsuit.  “Los Angeles County Probation failed to follow these mandatory provisions and increased the risk of injury and (danger) to decedents by their failure to implement the mandatory provisions.”

The lawsuit contends that after Pasasouk failed to meet with a probation officer twice in early 2012, no efforts were made to locate him until September, when he was arrested on suspicion of drug possession.

After that arrest, the District Attorney's Office recommended that  Pasasouk be allowed to enter a drug diversion program instead of being placed  back behind bars -- despite a lengthy history of convictions and a recommendation to the contrary by the Probation Department, according to the  lawsuit.

The District Attorney's Office issued a statement after the killings, admitting that it had erred in recommending that Pasasouk be placed in the drug diversion program.

Pasasouk was released from custody in late October or early November, according to the lawsuit.

“Approximately one month later, when decedents in the early morning hours went by to pick up a friend at the boarding house, the drug-crazed Pasasouk accosted them with a handgun, forced them to their knees and began  executing them for a wrongfully held belief that they had stolen his  property,” according to the lawsuit. “The decedents were friends and family members who had no connection to the boarding house but merely picking up a friend for a birthday celebration in Las Vegas.”

The lawsuit asks for unspecified compensatory and punitive damages.

Although the victims of the shooting were identified by the coroner's office, the lawsuit refers to Robert Calabia as Robert Navales, and names Teofilo Navales as Teofilo Banayos.