There is no single approach to defending a criminal case. Every set of facts is different, every prosecution has its own weaknesses, and every defendant brings their own circumstances to the table. The strategy that wins one case may have no place in another. Effective defense work begins with a careful analysis of the facts, the law, the evidence, and the strengths and weaknesses on both sides — and only then does an attorney determine which strategies offer the best path forward.
Below are the broad categories of defense strategies regularly used in California criminal cases. Most defenses fall into one of these four groups, and many cases involve a combination of multiple approaches.
Constitutional Defenses
Constitutional defenses challenge the way law enforcement gathered evidence or interacted with the accused. When officers violate a defendant’s constitutional rights, the evidence obtained through that violation may be excluded from trial — and without that evidence, the prosecution’s case may collapse.
Fourth Amendment challenges. The Fourth Amendment protects against unreasonable searches and seizures. If officers searched your home, vehicle, or person without a warrant, without valid consent, or without a recognized legal exception, your defense attorney can move to suppress whatever was found. This is a particularly common strategy in drug crime cases, where the prosecution’s entire case may depend on physical evidence seized during a stop or search.
Fifth Amendment challenges. Statements obtained without proper Miranda warnings — or after a suspect has invoked the right to remain silent — may be inadmissible. If a confession or incriminating statement was the centerpiece of the prosecution’s case, suppressing it can change everything.
Sixth Amendment challenges. Defendants have the right to counsel during custodial interrogation, the right to confront witnesses, and the right to a fair trial. Violations of these rights can serve as the foundation for motions to exclude evidence or even dismiss charges.
Factual Defenses
Factual defenses challenge the prosecution’s version of what happened. The goal is to create reasonable doubt about whether the defendant actually committed the offense.
Mistaken identity. Eyewitness testimony is far less reliable than people often assume. Memory is malleable, lighting and stress affect perception, and lineup procedures can suggest answers to witnesses. Where identity is the central question, a defense attorney may challenge the reliability of eyewitness testimony, present alibi evidence, or highlight inconsistencies in witness statements.
Lack of intent. Many criminal offenses require the prosecution to prove that the defendant acted with a specific mental state — for example, the intent to deceive in a fraud case or the intent to permanently deprive in a theft case. If the evidence does not establish that mental state beyond a reasonable doubt, the charge cannot be proven.
Insufficient evidence. Sometimes the prosecution’s case simply does not meet the burden of proof. The defense attorney’s job is to identify gaps in the evidence and force the prosecution to prove every element of the offense beyond a reasonable doubt.
Affirmative Defenses
Affirmative defenses do not deny that the act occurred. Instead, they argue that the defendant’s conduct was legally justified or excused under the circumstances.
Self-defense. Under California law, a person is justified in using reasonable force — including deadly force in some circumstances — to defend themselves or others from an imminent threat of harm. Self-defense is one of the most common affirmative defenses in assault and battery cases.
Duress. A defendant may argue that they committed the act only because of an immediate threat of serious bodily harm or death. Duress is rarely available but can be powerful when the facts support it.
Entrapment. When law enforcement induces a person to commit a crime they would not otherwise have committed, entrapment may be a complete defense. This issue arises in undercover operations, sting operations, and certain online investigations.
Mistake of fact. A reasonable, good-faith mistake about a fact that is essential to the offense may negate the required intent. For example, mistakenly believing that property belonged to you can defeat a theft charge.
Necessity. In limited circumstances, a defendant may argue that committing the act was necessary to prevent a greater harm.
Procedural Defenses
Procedural defenses focus on the legal process itself rather than the underlying facts of the case.
Statute of limitations. Most criminal charges in California must be filed within a specific period after the alleged offense. If the prosecution waits too long, the case may be barred entirely.
Speedy trial violations. Under California Penal Code § 1382, defendants have the right to be brought to trial within specific timeframes — generally 60 days for felonies and 30 to 45 days for misdemeanors. When the prosecution fails to meet these deadlines without good cause, the case may be dismissed.
Double jeopardy. A defendant cannot be prosecuted twice for the same offense. If a prior case ended in acquittal or certain types of dismissal, double jeopardy may bar a second prosecution.
Improper charging decisions. Some cases can be challenged based on errors in how the charging document was drafted, defects in the grand jury process, or other procedural irregularities.
Evidence Challenges
In addition to broader defense strategies, attorneys often focus on the integrity of specific pieces of evidence — whether the chain of custody for physical evidence has been properly documented, whether laboratory analysis was conducted reliably (an especially important issue in DUI and drug cases), whether eyewitness identifications followed proper procedures, and whether digital evidence has been authenticated and preserved correctly.
Choosing the Right Strategy
Determining the right defense requires a thorough understanding of California criminal law, deep familiarity with how local courts handle different types of cases, and the experience to recognize which arguments are most likely to resonate with prosecutors, judges, and juries. A San Diego criminal defense lawyer who has handled a wide range of cases knows when to challenge evidence, when to negotiate, and when to take a case to trial.
Attorney Elliott Kanter has more than 45 years of experience defending clients across California, including in Chula Vista and throughout San Diego County. If you are facing criminal charges and want to understand the strategies that may apply to your case, contact The Law Office of Elliott Kanter APC for a free consultation.