To be found guilty a defendant must be proven guilty beyond a reasonable doubt. The defendant has an opportunity to present a defense. Most of the time criminal defendant's say "I didn't do it" or "I did it, but...." There are very specific ways the these positions should be raised in court.
All people accused of a crime are legally presumed to be innocent until they are convicted. As a result, a prosecutor must convince the court (judge or jury) that the defendant is guilty AND that the defendant does not have to present a defense. Often a competent trial attorney may ask that his client remain silent, not present any witnesses, and the prosecutor failed to prove his or her case. Many defendants wrongfully believe that they should present their argument or testify to defend themselves. Although every defendant has an absolute right to elicit such a position, in most situations that tactic will hurt their case rather than help. An alibi defense if a situation where defense presentation of evidence is absolutely crucial. In an alibi situation, a defendant asserts that he was somewhere other than the scene of the crime at the time it was committed. It is important to remember that criminal discovery rules impose a different burden on the defendant if he presents an alibi.
In some situations, the defendant has committed an action that appears to be criminal but the law will justify or excuse the behavior. The most common instance of this defense is "self-defense.". Self defense is usually implied in crimes of violence, such as battery, assault with a deadly weapon, or murder. Again, there is a nuance necessary to presenting such a position. An experienced trial attorney will address: who was the aggressor, whether the defendant's belief that self-defense was necessary a reasonable one, and whether reasonable force was used.
Drug possession cases also involve another scenario where a person appears to have committed an offense but the law requires an acquittal. Frequently this occurs when police have discovered a person to be in possession of drugs but that discovery is the result of an illegal search or seizure. Illegal searches and seizures require a court to suppress or "throw out" illegally collected evidence. Without this evidence even if a person is clearly in possession of contraband, the court will be forced to find the defendant not guilty.
Procedural errors may occasionally result in dismissal. Some small errors may cause the court to disregard small portions of evidence but still allow a case to proceed. Other errors are so inconsequential that courts will ignore them. However, some procedures are constitutionally or statutorily required. Mistakes in these procedures may result in a court finding a defendant not guilty. Experienced trial lawyers carefully comb through evidence and the process to make sure all of a defendants rights have been safeguarded. As a former prosecutor, I know what the police and prosecutors are supposed to do. This perspective gives me an ability to know when a mistake has been made.
Although illegal searches and self defense are valid positions, many other excuses frequently fail. In Virginia. Defendants who commit crimes under the influence of drugs or alcohol sometimes argue that their mental functioning was so impaired that they cannot be held accountable for their actions. Voluntary intoxication however does not excuse criminal conduct. Courts may more severely punish a person for breaking laws aided by alcohol. Likewise, the defense of entrapment rarely succeeds. If the Court believes that a suspect was predisposed to commit the crime the court will disregard evidence that a government agent suggested the crime and helped the defendant to commit it.
The ability to discern the quality of potential defenses in a criminal case is one of the most crucial skills an experienced trial attorney can bring to a case. There is simply no substitute for years of trial experience. Some judges accept certain defenses while other may reject the same argument. I have practiced in more than twenty different jurisdictions and tried thousands of cases. Please contact me if you want to discuss whether one of these defenses might be useful in your case.