Criminal procedure: arraignment.

Senator Arreguín's proposal to codify Fourth Amendment protections requires courts to review all warrantless arrests within 48 hours to determine probable cause, addressing a gap in California law identified by the Committee on Revision of the Penal Code. The measure applies to both adult and juvenile arrests, mandating immediate release if probable cause is not established.

The bill outlines specific procedures for these judicial reviews, allowing courts to base probable cause determinations on sworn statements or police reports through remote or in-chambers proceedings. Courts must document the basis for each determination, including arrest timing, review dates, and materials consulted. While these initial findings do not bind courts in subsequent proceedings, they create a formal record of the probable cause assessment.

For juvenile cases, the legislation adds parallel requirements to the Welfare and Institutions Code, replacing current provisions that permit extended review periods. The new standard matches adult procedures, requiring notification of release orders to the minor, their custodian, and defense counsel when probable cause is not found. The bill preserves existing provisions allowing peace officers to release individuals without magistrate review in specific circumstances, such as insufficient evidence for criminal complaints or cases involving substance use treatment.