If a person confesses to committing a crime???

No they don't. I am sur there are cases where someone cofessed to a crime they didn't commit due to pressure from the police or to protect someone else. A good defense attorney can make these arguments and if a jury feels that is reasonable doubt the can find the person innocent. A jury does not decide if a crime was committed, they decide guilty or innocent.

It depends on what the investigator finds as evidence and if the investigator has probable cause to place the person at the scene of the crime. The case would not go forward for a Judge to find probable cause to prosecute nor can a Jury be selected if the investigative reports (doubtfully) did not determine that a crime was committed. However, the person confessing to commiting to the crime will forever be watched to see if he or she is a compulsive prankster. If that is the case, the person confessing can cause more serious problems because Judges, Attorneys and Law Enforcement Officials do not like it when a person waste the legal system resources.

I strongly advise you to tell him or her if they continue to "cry wolf" there might come a time when he or she will need serious advise and no one will believe him or her if they are involved in a crime but did not actually not commit the crime.

A confession is just another piece of evidence in a case. The finder of fact (judge or jury) determines the weight to give the evidence/confession and can entirely disregard it if they choose. A confession does not mandate a guilty verdict. Not guilty is always a possible verdict no matter what evidence is presented. However, as a general rule, a confession makes a not guilty less likely.

I believe a judge is probably bound by law to convict but a jury in America has the right to rule not guilty if they so chose, even if the accused confesses

There still has to be evidence aside from a confession in order to convict. It's actually surprisingly common for some suspects to confess to a crime that they didn't commit due to mental insanity or alterior motives like protecting a boyfriend.

I believe if they have a confession they would have to convict him.However sometimes if the confession was made under duress the defense attorney can argue and he could be released

if the Jury votes that way.

it is passable, if there is no evidence and there is reason to believe that someone else did it but usually once someone admits to a crime the police stop investigating and believe that person did the crime they admit to. there have been many cases in the media about this. just recently a man admitted to killing Jon bonnet Ramsey but it was proven that it was not passable for him to have committed the crime. some people admit to crimes they did not commit to receive attention.

It would depend on what the crime was and whether it was intentional or not. Pleading guilty usually gets the guilty person a plea deal on a lesser charge, but you may want to check your specific state. My state is inundated with plea deals :(

It can be used as evidence. But a confession alone is not enough for a conviction. There must be corroborating evidence.

Not at that moment. I would have to investigate and find evidence to back up the person's story.