A Pitchess motion (from Pitchess v Superior Court, 11 C3d 531 (1974)) is a special type of motion for discovery that requests information from a police officer's confidential employment file. The need for this motion usually arises when the defendant alleges police misconduct. The type of information generally sought after with the Pitchess motion includes personnel records which show prejudicial acts, falsifying evidence and/or testimony, and the use of excessive force while on the job. To be successful on this motion, defense counsel must be able to establish that this information will pertain to some aspect of the defense.
Based on the Pitchess case, California Evidence Code sections 1043 to 1046 provide avenues to obtain some of the information which is sought by a Pitchess motion. Under these provisions, when defense counsel seeks to obtain officer personnel records they must file a written motion with the court. The written motion must be accompanied by other documents to be valid such as: a notice of the motion, a declaration or affidavit, police report copies detailing the detention and arrest of the defendant, and the proof of service.
The most detailed part of filing a Pitchess motion is the affidavit. Under California Evidence Code section 1043(b)(3), the affidavit must be based on “good cause” by demonstrating sufficient facts which show why such information is necessary and relevant to the issues in the defense's case. The relevance between the information sought and the specific defense theory must have a strong link to prove such information will be material, and thus establish good cause. The court will determine whether good cause exists at a hearing where the agency holding the record, the district attorney, and the defendant and his/her attorney discuss the matter.
Under California Evidence Code sec. 1045, once the court is satisfied that good cause exists, it must then look at the evidence sought and determine whether it is indeed relevant to the defense's case.
The court's analysis is done through an “in camera” hearing, meaning that it is conducted outside of the presence of the jury and counsel. This hearing must be held by the court if the defendant shows that it was possible that the officer engaged is some sort of misconduct. Usually facts are alleged by the defense which shows how officer misconduct could've occurred. The defense may establish this by merely providing a different recitation of the factual circumstances, or may deny the facts as presented in the report by law enforcement. Garcia v Superior Court, 42 C4th 63, 72. In this examination, the court does not act as the trier of fact and thus will not determine credibility or weigh evidence. 
Where the judge agrees with the defense that the information is relevant, an order is issued to disclose the information. Generally, the court will only mandate the disclosure of the names and contact information for witnesses involved in previous events with the officer. However, there are ways for the defense to get the actual reports of the incidents under certain circumstances, i.e. the witness is not available, the witness doesn't remember, or refuses to discuss the incident.
Certain information is precluded from disclosure in a Pitchess motion. This includes events that happened too remotely in time, or the conclusions noted by internal affairs officers during the police investigation. Yet some of this information may still be available to the defense if it can show it relates to exculpatory information as provided by the Brady case. Other information that is not disclosable is the personal information of the officer such as his/her place of residence.Hackett v Superior Court, 13 C4th 96 (1993).
Under a central case dealing with Pitchess motions, Alford v Superior Court, 29 C4th 1033 (2003), the court is required to order the recipient of Pitchess materials to not disclose them for any other purpose. Additionally, Alford holds that the district attorney will not automatically get access to the Pitchess documents. Protective orders may be issued to ensure the continued secrecy of the information involved. However, a protective order will only be issued if there is good cause to support it.
California Evidence code 1040(b) generally allows the government (i.e. law enforcement) to exercise a privilege over confidential information for which disclosure is against the public interest. Normally, to achieve the disclosure of such information, one needs to show that the interest to the public outweighs the agency's need for disclosure. The use of a Pitchess motion can sometimes obtain access to the information even if the privilege is found valid. A law enforcement agency can be subject to discovery sanctions if it does not turn over the information in favor of continuing a claim to privilege. The situation can lead to a dismissal of the prosecution's criminal complaint where there is no valid claim to privilege and the agency still refuses to provide the info requested.
Whenever the prosecution appeals the allowance of a Pitchess motion, the appellate court will look to see if an abuse of discretion occurred. If the previous court denied the motion without conducting its in camera review, the appellate court can choose to remand the case and require the in camera hearing. A reversal of the denial will only occur where the court has in fact done an in camera hearing and subsequently denied the motion.
Pitchess motions can be used in DUI cases where a defendant believes the officer engaged in some sort of misconduct during the DUI investigation. This often occurs where there was some type of undue aggressiveness by police. A defense attorney will use the Pitchess motion process described above to obtain information about the officer's past misconduct and inclination to treat suspects in an abusive manner. The Pitchess information can also be used to show past prejudicial acts by the officer, or a pattern of falsifying evidence. If you believe any of these situations occurred in your case, it is important to inform your criminal defense attorney to determine if a Pitchess motion will help your defense.
 Warrick v Superior Court, 35 C4th 1011 (2005)
 People v Gaines, 46 C4th 172 (2009)
 City of Los Angeles v Superior Court, 29 C4th 1 (2002)
 Dell M v Superior Court 70 CA3d 782.
 People v Gaines 46 C4th 172.
 People v Memro 38 C3d 658