Why is the burden of proof different for police and prosecutors, or for an arrest or conviction?
An arrest is not a conviction. Formal charges are not a conviction.
The police are looking for a suspect and information that they can pass to the district attorney - the prosecutor - and say, "this person probably did the crime."
The evidence upon which they base those decisions isn't subjected the scrutiny of a jury or judge trial, and in most instances, the person isn't represented by a criminal defense attorney.
It is simply enough for the police to be able to say, "we have probable cause" or "this guy probably committed the crime."
That's enough evidence to arrest the suspect, charge him or her, and start the prosecution process. Then the suspect is released unless the charge is a felony. That isn't enough evidence to convict the person and take away his or her liberties.
Conversely, the district attorney seeks to charge a person with a crime when he or she has been told by the chief of police that they have enough evidence to support the charge and the DA looks at the evidence and concurs. The DA should be more than "probably" sure that the alleged defendant committed the crime. The DA will look at the evidence from the standpoint of the probability of obtaining a conviction.
At the next level - the trial - the burden of proof is even higher. At that level, the judge in a bench trial or the jury in a jury trial must be convinced beyond a reasonable doubt that the person committed the crime.
A person is innocent until proven guilty. If they are proven guilty, their personal liberties will be restricted. Our system guarantees people who are accused of a crime the right to face their accusers, to cross examine the witnesses that accused them of the crime, to examine the evidence presented against them, and to provide their own witnesses. People also have the right to give testimony on their own behalf or to refrain from taking the stand.
That level of proof and cross examination cannot occur in the district attorney's office, nor can it occur in the police station. It can only occur during a trial.
During a recent interview by Wisconsin Channel 3000 with Attorney Chris Van Wagner, TV3000 examined this very issue as it related to a recent arrest of a "suspected" sexual assault offender. Shortly after the arrest, police questioned whether the arrested suspect even could have committed the crime - the facts just didn't fit. Police released their suspect, but tied him to a tether and monitored his actions.
In another interview, Attorney Chris Van Wagner analyzed Scott Jensen's new trial. In that situation, evidence in the first trial that should have been presented to the jury for their consideration was not. When evidence is withheld - particuarly when it is critical to the jury's decision - justice has not been served. See Jensen's Trial for more information.
