Officials also say that Saito had sexual relations with staff members at the hospital that was brought to light in documents from 1993, KGMB reported.
The hospital is also being questioned as to why it took hours for them to report Saito missing.
Saito was seen on surveillance video climbing into a cab at 9 a.m. local time. He then boarded a charter flight from Honolulu to Maui and then got on board a flight from Maui to California, landing on the mainland at about 5:30 p.m. Hawaii time. Authorities were notified of Saito's escape at 7:30 p.m. local time, with them alerting the community nearly an hour later, KGMB reported.
In 2000, his attorneys tried to get Saito a conditional release. But a deputy city prosecutor objected, saying that Saito "fills all the criteria of a classic serial killer," The Associated Press reported.
He also had been permitted to be escorted home for weekend conjugal visits over a two-year period and his trips away from the mental hospital inspired a law change in 2003 when a state's attorney general's office found that mental patients at the state hospital didn't' have a legal right to conjugal visits, The AP reported.
A multi-agency manhunt is ongoing. Officials are not sure if Saito is still in California.