A common misunderstanding is that if you get released from jail without charges, then you will never be charged at a later time. While it is certainly possible that you may never face charges later, the more likely answer is that the prosecution did not get charges filed against you in time. Either that, or the officers typically book and release people in situations like yours.
In a DWI arrest for example, the officer often takes you to the police station for breath testing or to the hospital for a blood test (urine tests are becoming incredibly rare). After testing, if your breath test revealed an alcohol concentration under .16 and no aggravating factors are present, then you are only subject to a 4th Degree DWI, which is a misdemeanor level offense. In the overwhelming majority of those cases, the officer will release you from custody. Sometimes, they will give you a citation that lists the charges against you. Other times, you will receive the charges in the mail with a notice of a court date.
In Gross Misdemeanor, or Felony, level DWIs, the law enforcement agency may very well decide to hold you in jail until you see a judge so that conditions of release or bail is set. However, in some gross misdemeanor DWI cases, the officer will release you without any charges. It is then often up to the prosecution to file a complaint with the court that lists the charges against you. Once that happens, the court sends you a copy of the charges and a notice of a hearing to you to your last known address. In some circumstances, the prosecution will file a complaint warrant. This means that once the charges are filed, a warrant is issued. Often, a complaint warrant will include an amount of bail that you can pay to clear the warrant and get a court hearing date scheduled. Otherwise, you may have to turn yourself in to the county that issued the warrant. If that happens, then you often have to wait until you see a judge to have bail set or conditions of release.
The thirty-six- and forty-eight-hour rules play a large role in why people get released without any charges in gross misdemeanor and felony cases. Under the thirty-six-hour rule, a person arrested must be brought in front of a judge or charged without unnecessary delay. Importantly, a person’s thirty-six hours does not include the day of arrest, legal holidays, or Sundays.
Under the forty-eight-hour rule, a judge must make a probable cause determination on the person arrested without unnecessary delay. Different from the thirty-six-hour rule, a person’s forty-eight hours starts immediately upon arrest. Whether a person is in jail on a Sunday or legal holiday does not matter for this rule. Practically, probable cause is often found by a judge for a person to be continually detained. However, it is not entirely uncommon for a person’s forty-eight hours to expire, be released, and charged at a later time.
If you are wondering how long the prosecution has to charge you without violating the statute of limitations, then you need to look at the statute governing these time periods. The most serious violent felonies will often have no statute of limitations, which allows the prosecution to bring charges at any time. Most misdemeanors and gross misdemeanors carry a three-year statute of limitations. If a prosecutor charges you after the statute of limitations expires, then you may have grounds to get your case dismissed. Importantly, the statute of limitations applies for when you are charged. If you let your case go to warrant status at any point, or otherwise do not resolve your case within the statute of limitations, then you will very likely not have an argument for dismissal based on this rule.