The standard for Probable Cause is extremely low. Probable Cause for arrest exists where the facts and circumstances known to the arresting officers are sufficient to cause a reasonably cautious person to believe that the suspect was guilty of committing a crime. The standard of weighing the evidence for probable cause is far lower than the standard of weighing evidence required for a conviction beyond a reasonable doubt.
At a minimum, a Probable Cause Affidavit must state facts establishing that a defendant has committed each of the elements of the charged crime. Thus, an affidavit in support of Second Degree Murder must state facts establishing that 1) the victim is dead; 2) the victim’s death was caused by the criminal act of the defendant; and 3) the killing was accomplished through an act “imminently dangerous to another and demonstrating a depraved mind.” This last element requires an act that: (a) a person of ordinary judgment would know is reasonably certain to kill or do serious bodily injury to another; (b) is done from ill will, hatred, spite, or an evil intent; and (c) is of such a nature that the act itself indicates an indifference to human life.
A person is “immune from criminal prosecution and civil action,” if a person justifiably used deadly force. This is an extraordinarily important aspect of the law, because immunity provides a greater level of protection than an affirmative defense. In the case of an affirmative defense, the accused must go to trial and convince a jury that he acted justifiably. With immunity, the case will never get to a jury in the first place. In order to win immunity, the accused need only convince a judge, by a preponderance of the evidence, that the killing was justified.
Over the course of American history, the words of the Fourth Amendment have never changed. The meaning of those words, however, have changed dramatically and for more read about Georgetown criminal defense.