How Does Criminal Justice System Work

The criminal justice system can be very confusing, particularly for those who have had limited prior experience with law enforcement or the court system.  This overview is designed to provide a brief summary of what the various parties do and how the system works.




 When the police contact someone they suspect is involved in criminal activity, they can either arrest the person and take them to jail, or issue them a citation (a “ticket”).


 If the person is arrested, they may be held in custody until the district attorney files charges.  They can also post bail and be released with a date to appear in court.  It is also possible for the person to be released by the jail with a future court date.


 If the person is issued a citation, they will sign a promise to appear in court on a specified date.




 After the police cite or arrest someone, they usually write a report.  This report will outline the events that took place and provide information as to why the officer believes that a crime has been committed.  The officer will usually recommend that certain charges be filed by the district attorney.


 The police report is given to the district attorney for review.  A deputy district attorney (DDA) will review the case and decide whether or not to file criminal charges.  The DDA has the discretion to file all, some, or none of the charges recommended by the police.  The DDA may also choose to file additional charges not suggested by the police but still supported by the evidence.  If the person is in jail and the DDA decides not to file charges, they will be released from custody.  The DDA may also request law enforcement conduct additional investigation before filing the case.


Crimes in California are classified as infractions, misdemeanors, or felonies.  An infraction is punishable by a fine only.  Punishment for a misdemeanor can result in up to a year in county jail.  A felony is the most serious class of crime and may result in incarceration in state prison.  Part of the filing decision made by the DA will include determining the appropriate level of the offense (infraction, misdemeanor, or felony).  Almost all of the cases the district attorney’s office files are either misdemeanors or felonies.






 A person who has had criminal charges filed against him or her is referred to as a defendant.  The first court appearance in a criminal case is called an arraignment.  A deputy district attorney will be in court to represent the People of the State of California.  At the arraignment the judge will tell the defendant what he or she is charged with.  The defendant will also be informed of his constitutional rights.  He may choose to hire an attorney to represent him.  If he cannot afford an attorney, the judge will appoint an attorney to represent him. 

 If the defendant is in custody at the arraignment, the judge will either set a bail amount or release the defendant on his “own recognizance” with a promise to appear in court for future dates.  In certain rare circumstances the judge may also order the defendant held in jail without bail.

 At the arraignment, a defendant will usually enter a plea.  The most common pleas for a defendant to enter at arraignment are guilty, not guilty, or no contest.  Frequently the plea at the this stage is not guilty, particularly in felony cases.



After the Arraignment


 The criminal process after arraignment differs between felony and misdemeanor cases.     

Misdemeanor Cases

  If the defendant enters a not guilty plea at arraignment, the case proceeds toward trial.  At a trial, the prosecution (represented by the district attorney’s office) has the burden to prove the defendant guilty.  The defendant has no obligation to present any evidence supporting her innocence.  Usually a defendant is represented by an attorney at this point.  The prosecutor and the defense attorney will exchange information such as police reports, witness statements and other evidence in a process called “discovery”.  The attorneys will also discuss possible resolutions to the case in what is informally referred to as “plea bargaining.”  If a defendant agrees to a plea bargain, that means he or she is agreeing to resolve the case by waiving (giving up) the right to a trial and receiving an agreed upon punishment.


If there is no agreement reached and the case is not dismissed for some other reason, the case will proceed to trial.  At a trial, the prosecution is required to prove the defendant guilty beyond a reasonable doubt to a jury.  Sometimes the parties agree to have a judge make the decision instead of a jury.  If the defendant is found guilty at trial, a judge will sentence the defendant.  This means the judge will impose a punishment for the crime.  A sentence in a misdemeanor case could include jail time, a period of probation, and other terms and conditions such as required counseling or search terms for drugs and alcohol.


Felony Cases


 After a defendant pleads not guilty in a felony case, the case is set for a preliminary hearing.  A defendant has a right to have a preliminary hearing within 10 court days or 60 calendar days of his arraignment.  He can also waive his right to have the preliminary hearing within these time periods.


A preliminary hearing is a hearing held in front of a judge where the prosecution is required to put on evidence that shows the defendant committed the crimes with which he is charged.  The prosecution has the burden of proof, but the burden is not as high as the proof beyond a reasonable doubt required for guilt.  If the judge finds that enough evidence has been presented, he will have the defendant “held to answer” for trial.  The case will then proceed to jury trial.  The discovery and plea bargaining processes outlined above also take place in felony cases.


If the felony case does not resolve through a plea bargain, the defendant will go to trial.  At the trial, the prosecution has the burden to prove the defendant guilty beyond a reasonable doubt.  The defendant does not have to prove his innocence.  The trial is usually conducted with a jury.  The jury’s job is to decide whether the defendant’s guilt has been proven.


Jury Trial and Sentencing


 In both felony and misdemeanor cases, both the defense and the prosecution have the right to a jury trial.  A jury trial starts with jury selection.  In this process, the prosecutor and the defense attorney pick jurors who can fairly hear the case.  After the jury is selected, the attorneys give opening statements in which they explain what they believe the evidence will show.  Following opening statements, the prosecutor will present the testimony of witnesses.  These witnesses will be questioned by the attorneys and will tell the jury the information they have that is relevant to the case.  After the prosecution presents its witnesses and evidence, the defense also has an opportunity to produce evidence, but they are not required to do so.  After all the evidence has been presented, each side presents closing arguments in which they summarize the facts and law of the case.  At this point, the jury is sent out to deliberate on the case.


If the jury is able to reach a verdict, they find the defendant either guilty or not guilty.  If they find the defendant not guilty, the case is over.  If the defendant is found guilty, the next step is sentencing.


Sentencing is the process by which the judge decides the appropriate punishment for the defendant.  Sentencing usually takes place at least several weeks after the guilty verdict.  At the sentencing, the judge will consider information presented by the prosecution and defense as well as information from a sentencing report prepared by the probation department.  In a felony case, punishment can range from probation and a sentence in county jail up to imprisonment in state prison.