California Penal Code Section 148 makes it a criminal offense to willfully resist, delay, or obstruct police officers and firemen when they are performing their duties. The punishment varies with the degree of the offense, as a misdemeanor or a felony. Some of the offenses are “wobblers," meaning that the crime may be punishable as either a misdemeanor or felony. The reason that resisting a peace officer of firefighter is a crime is based on the principle of public safety, and the importance given to these professions in performing their duties for the public. However, firefighters and police officers may exceed the scope of their employment, such as using unlawful force, which affects the defenses available to the defendant when charged with this offense.

Section (a) (1) states, “Every person who willfully resists, delays, or obstructs any public officer, peace officer, or an emergency medical technician … in the discharge or attempt to discharge any duty of his or her office or employment, when no other punishment is prescribed, shall be punished by a fine not exceeding one thousand dollars ($1,000), or by imprisonment in a county jail not to exceed one year, or by both that fine and imprisonment."

Section (2) states, “Except as provided by subdivision (d) of Section 653t, every person who knowingly and maliciously interrupts, disrupts, impedes, or otherwise interferes with the transmission of a communication over a public safety radio frequency shall be punished by a fine not exceeding one thousand dollars ($1,000), imprisonment in a county jail not exceeding one year, or by both that fine and imprisonment."

Section (b) states, “Every person who, during the commission of any offense described in subdivision (a), removes or takes any weapon, other than a firearm, from the person of, or immediate presence of, a public officer or peace officer shall be punished by imprisonment in a county jail not to exceed one year or in the state prison."

Section (c) states, “Every person who, during the commission of any offense described in subdivision (a), removes or takes a firearm from the person of, or immediate presence of, a public officer or peace officer shall be punished by imprisonment in the state prison.

Section (d) states, “Except as provided in subdivision (c) and notwithstanding subdivision (a) of Section 489, every person who removes or takes without intent to permanently deprive, or who attempts to remove or take a firearm from the person of, or immediate presence of, a public officer or peace officer, while the officer is engaged in the performance of his or her lawful duties, shall be punished by imprisonment in a county jail not to exceed one year or in the state prison.

In order to prove a violation of this subdivision, the prosecution shall establish that the defendant had the specific intent to remove or take the firearm by demonstrating that any of the following direct, but ineffectual, acts occurred:

(1) The officer's holster strap was unfastened by the defendant.
(2) The firearm was partially removed from the officer's holster by the defendant.
(3) The firearm safety was released by the defendant.
(4) An independent witness corroborates that the defendant stated that he or she intended to remove the firearm and the defendant actually touched the firearm.
(5) An independent witness corroborates that the defendant actually had his or her hand on the firearm and tried to take the firearm away from the officer who was holding it.
(6) The defendant's fingerprint was found on the firearm or holster.
(7) Physical evidence authenticated by a scientifically verifiable procedure established that the defendant touched the firearm.
(8) In the course of any struggle, the officer's firearm fell and the defendant attempted to pick it up."

Defenses

Police officers may not use excessive force, such that their behavior itself becomes a criminal offense. The Penal Code provides for this, stating “This section shall not apply if the public officer, peace officer, or emergency medical technician is disarmed while engaged in a criminal act."

Peace officers are only allowed to use “reasonable force" to affect an arrest, prevent escape or overcome resistance. Reasonableness is not determined from the officer’s subjective point of view, but rather what a reasonable officer in the same or similar circumstances would have deemed reasonable. In addition, officers may make an arrest only when a public offense has been committed. This means that if it is a misdemeanor, it must have been performed in the officer’s presence. An exception to this is a DUI arrest.

Police officer’s may make an arrest for felonies, even if the officer did not witness the commission of the felony. A felony arrest may be made with or without a warrant. An arrest warrant must be signed by a magistrate and supported by probable cause. The arrest must be made in a reasonable time, or else the warrant is considered “stale" and invalid. If a person is arrested in their home, the law requires that police have a valid arrest warrant, unless there are “exigent circumstances," meaning that there was an emergency. However, police officers can arrest without a warrant as well, so long as they have probable cause or good reason to believe that the person arrested committed a felony. Thus, police officers may not make an arrest where they cannot substantiate good reasons and probable cause. In a jury trial, the prosecution must proved beyond a reasonable doubt that the arrest was lawful. It is up to the jury to determine the reasonableness of the arrest.

A citizen’s resistance to an invalid arrest is considered self-defense. Thus, if the self-defense itself was reasonable, it is justified, and lawful. For example, if the person defended himself with his hands only, when facing rough treatment by the officer, this is reasonable. But it is unreasonable to use deadly force against such an officer. For example, using a rock or bottle to strike the officer would be an unlawful use of force, taking it out of the realm of self-defense.