In 1975, the Central District of California initiated Pretrial Services, after being named one of the ten nationwide demonstration districts. The success of the research project lead congress to enact the Pretrial Services Act of September 16, 1982, which was updated on October 12, 1994. Title 18 U.S.C. 3152-3156 establishes and defines the functions of Pretrial Services. On June 1, 1988, Pretrial Services in the Central District of California became an independent agency of the court, with Mr. John W. Luymes being appointed the first Chief U.S. Pretrial Services Officer in the district. Thomas W. Nuelle was appointed the second chief on March 25, 1996. George M. Walker was appointed the third chief on April 10, 2000. In October 2018, the United States Probation and Pretrial Services Offices in the Central District of California became one agency; currently, Jeffrey Thomason is the Acting Chief Probation & Pretrial Services Officer.
Pretrial Services performs two major functions:
1. INVESTIGATION and verification of each defendant's suitability for release on bail, considering  the risk of nonappearance for future court appearances, and  the danger he/she presents to the community and/or him/herself.
2. SUPERVISION of those persons released on bond. Those who are released on bond may be subject to conditions of release which requires them to report to a U.S. Pretrial Services Officer. Additional conditions may include travel restrictions, employment/education requirements, drug and/or alcohol testing, placement in a residential substance abuse treatment program, mental health treatment, internet restrictions, and/or location monitoring. The court is promptly notified of any alleged violation of release conditions with a recommendation for appropriate action.
Pretrial Services provides the judicial officer, who sets bail or reviews a previous order, with a written report giving verified information when available regarding the defendant's community ties, employment, finances, health, and prior arrest record.
Copies of the written report, which includes a bail recommendation and appropriate release conditions, where applicable, are provided to both the government and defense counsel at the time of the hearing. It should be noted that by statute [Title 18 U.S.C. 3153c, 1-3], information obtained in the course of performing pretrial functions is confidential and can only be used for purposes of bail determination, and is governed by confidentiality regulations. This information is not admissible on the issue of guilt in any criminal proceedings unless for perjurious statements made to secure pretrial release, or for failure to appear at subsequent court hearings during the pendency of the case.
One of the important functions of Pretrial Services is to report any apparent violation of release conditions promptly to the court and the U.S. Attorney, giving a recommended course of action [e.g., warrant, citation, or hold in abeyance].
It is of interest to note that failure to appear has not been a significant problem in the Central District of California during the years of operation.