The Prosecutor's Prerogative
So now you've got your definition of probable cause and you are going to have the elements of the crimes that, coupled with a little luck, may keep you out of a lawsuit. But keep in mind that many times district attorneys and state attorneys make determinations on whether or not to prosecute based on different criteria than officers do in making arrests.
As officers, we arrest the people who break the laws. The prosecuting attorneys, however, do not always want to prosecute all of these cases.
Why? Because sometimes they think it is an iffy case and don't want to lose. Sometimes, they just don't like the charge or don't like the facts. Like it or not, it is their prerogative, not yours.
Unfortunately, many times when the prosecuting attorney decides to not file the case, this emboldens the criminal/arrestee, and he now wants to get back at the officer. So he goes to see some-pardon the expression-attorney, who decides to sue the police.
The good news is that most of the time the fact that the prosecuting attorney did or did not go forward with the case cannot even be entered as evidence in a civil suit against an officer and is really of no legal consequence.
Further, even if the prosecuting attorney puts it in writing that he or she believes that the officer did not have probable cause, that fact is also not of any consequence because it is up to the judge in the civil suit or the jury to determine whether the officer had probable cause to make the arrest. In federal cases when the officer is sued individually, the standard for qualified immunity (getting out of the suit) is arguable probable cause, which means that the officer did not actually have to have probable cause, only a reasonable/arguable belief that he thought he had probable cause for the arrest.
Along with false arrest, lawsuits against cops almost always include an allegation of excessive force or battery. If you, the officer, did not have probable cause to arrest the suspect, then you also did not have legal authorization to use force and lay hands (Taser/baton/OC) on the person, thus use of force becomes an almost automatic component.