Not all criminal cases go to trial. In fact, more often than not, a criminal case will be disposed of prior to a trial. Plea deals are common because they can be beneficial for both the defendant and the People.
But, there are also circumstances when a case can be dismissed prior to a trial. One common motion that can be brought during the pre-trial stages of a case is a Motion to Suppress. Penal Code section 1538 provides the right of an accused to challenge evidence that may have been obtained illegally. Typically if the evidence is suppressed -- like the blood results of a DUI stop -- the case must be dismissed because the evidence is dispositive to the case.
One example of when a Motion to Suppress could be successful is when an officer stops an accused for a traffic stop that was unlawful. An officer cannot stop an individual without sufficient probable cause, a legal standard provided by the Fourth Amendment. Thus, if an officer reports that he stopped an accused for violating the Vehicle Code, but there was no Vehicle Code violation, the accused may be able to prevail at a P.C. 1538 hearing.
A criminal defense attorney has the responsibility to perform an adequate investigation. Evidence obtained by an attorney could lead to a decision to file a Motion to Suppress. An investigation can include, but is not limited to: requesting discovery from the prosecution, subpoenaing documents, and looking at possible video surveillance. It is now common for officers to have dashboard cameras, and also cameras on their persons. A video could show that a traffic stop was unlawful.
Some of my clients have asked what a motion consists of. A motion is a request for the court to do something. The party "moves" the court to make an order. A motion is started (usually) by an opening brief. The attorney files a memorandum with points and authorities (cases in support of the motion). Then, the prosecution (again, usually) files an opposition brief, highlighting their position against the motion. This allows the court to familiarize itself with the law and facts of the particular case. After the briefing with physical documents, there is an evidentiary hearing where witnesses testify. The arresting officer most likely will testify as to the facts of the stop or arrest.
A Motion to Suppress is a constitutional protection. It safeguards citizens from police abuses. There are other type of situations, as well, when a P.C. section 1538 may be appropriate. Law enforcement cannot exercise a warrant based on false information. Police cannot execute a warrant outside the constraints of the warrant. Facts should be scrutinized in every criminal case.
In conclusion, a defendant may not need to persuade a jury. There are pre-trial motions that can be potentially made, which could lead to a complete dismissal. It is important to contact an attorney should you be charged with a crime. We welcome your calls and questions.