All DUI cases start out with a police report, blood test or breath test results and if the case involves an accident, a collision investigation report detailing the specifics of the incident. Once these documents are prepared they are submitted to the local prosecutor for evaluation and determination of possible criminal charges. The District Attorney will file what is called a formal " complaint" with the local Court that alleges the crimes charged and what they intend to prove. Sometimes, however, the complaint is not filed before the date given to appear in Court. When this occurs the person will be sent a new Court date.
Why does this happen? Usually the arresting agency will not have submitted the necessary paperwork to the DA in order to file the case. This paperwork may include the results of a blood test or other chemical test given. In many cases there is a backlog at the local crime lab that does the analysis, sometimes the test is complete but the arresting agency is backlogged and simple hasn't submitted the final reports to the District Attorney. In some situations the DA has all of the reports but needs additional time to evaluate the evidence. Sometimes, the file is sent back to the arresting agency for more information or the DA may require some additional investigation to finalize their decision on what charges, if any, to file. For example, a witness may need to be re-interviewed or some additional evidence may need to be tested. In any case, the DA will usually notify the accused by way of a letter once the case is finally submitted and a new Court date will be issued.
It is important to remember that California Law gives the prosecutor one year to file a misdemeanor DUI and three years to file a felony charge. If the prosecuting agency fails to file charges within this period of time then they will be barred by the statute of limitations.
During the period of time between the investigation and the formal filing of charges the DA is under no obligation to release any information or reports. All official reports will be turned over to the defense attorney only once the complaint is filed with the Court.