You press charges for generally two reasons most of the time (a lawyer can correct me on this)
1. There is a sense a conviction can be achieved
2. They can be used to leverage a plea
Now just because I can’t convict someone (an especially big challenge in DV cases), doesn’t mean the thing didn’t happen. Before 1970, one could not rape their spouse in a legal sense. But you bet it could happen. And courts don’t aim to take on really long shot cases just because.
Innocent until proven guilty ends up being a rather narrow guiding principle. It just is. Innocent people can be put in pretrial jail for months on end until it’s easier to say they’re guilty to something lesser just to ease the financial burdan. Likewise, by its nature, it means many guilty people will not be found that way by any system.
I've never seen a case charged based on a sense of conviction. (no offense to the remark) Going to trial? Now that requires the DA to look at the case again and evaluate the stakes. It is quite embarrassing, unethical and damaging to a DA's office to charge people with crimes which can't get past go. Go=probable cause. You only charge when you have PC. You don't have it (even with a sense of guilt by the defendant) you gotta go get it.
Once a person is arrested (and in custody), that person must be brought before a judge or magistrate within 48 hours. At that point the State must produce a criminal complaint demonstrating there is a probable cause that the charging crime was committed (must identify the criminal statute) AND probable cause that it was committed by the defendant. This is typically presented on a few pages, describes the who what when and where, and it must be signed by some sworn official (usually a law enforcement officer, or prosecutor (sometimes a game warden). If they can't do this, the person is released from custody immediately. If State can get to this stage later, they can summon the person, or issue an arrest warrant. (This is common in DV, when a victim comes forward a day or few days later).
It is at this time the person is read the charges, right to atty, etc. Then bail is determined. A case like this, probably not cash bail, but certainly all kinds of no contact conditions. Defendant signs signature bond, leaves, comes back for next appearance (arraignment), where they formally plead NG (usually). In between Bail Hearing and Arraignment, this is the likeliest time the Defendant and DA discuss any plea bargain, if any is offered. This is also when the DA typically learns whether or not the Victim is A. reliable, and B. going to testify. You can count on the Defendant telling his/her lawyer, 'she ain't going to talk'. Again, defense counsel stressed on this point too. Who's for real?
Plea bargains in DV and OWI cases are extremely closely examined by DAs office, every women's group in the public, MAAD, etc. In any other non-violent crime, yes, plea bargains are valuable tools of efficiency, supported by both sides of the bar, and the courts. What are you really pleading 'down' to, when you have a unreliable witness in a misdemeanor battery case. Criminal Disorderly Conduct is a 'fav' of the State.
#For sake of discussion, let's assume the charges are misdemeanor, and not felonies (which would require either an indictment by a grand jury (filing of an 'Information') or a preliminary hearing (a mini probable cause hearing). That's where a defendant could very well be 'in custody' because there's cash bail which they can't post, for an extended period of time, but of course, they could exercise their right to a speedy trial. That means the Preliminary Hearing has to take place in 10 days, with trail to follow 20 days later. Majority of DV cases are charged as simple battery. Substantial battery (felony assault) would bring all of this into play. A plea bargain at this level, is incredibly scrutinized, only signed off on by Deputy or above, and usually not w/o full support of the Victim Witness Coordinator.