The United States’ current federal criminal procedure rules allow for liberal joinder of charges. This means that prosecutors – the officials that decide who to charge with crimes and what crimes to charge them with – can bring many charges against a single defendant at once. The practice of bringing a large number of often redundant charges against a defendant is known as charge stacking. Prosecutors derive much of their power to coerce defendants into taking plea bargains from charge stacking. Legislators in the United States have defined so many crimes – many of them overlapping acts that have already been criminalized – that almost any criminal act can result in multiple charges, each with its own punishment. For example, burglary is a crime, but so is possession of burglar’s tools (such as a lock pick or screwdriver) with the intent to commit burglary.

Prosecutors know this and take advantage of it; in the burglary example, let’s say that burglary carries a penalty of up to three years in prison and possession of burglar’s tools can be penalized by up to two years. A prosecutor can charge someone arrested for burglary with both, threatening them with up to five years in prison. Facing such a lengthy prison sentence, the defendant is much more likely to take a plea bargain than if she were facing only one charge. What’s more, the plea bargain will probably be less advantageous than it would have been had the defendant been charged with only one crime.

At trial, courts are mindful of the dangers of allowing prosecutors to charge defendants with so many crimes at once. As the New Jersey Supreme Court outlined in State v. Reldan, multiple charges can prejudice the jury against the defendant in a variety of ways: it could make if difficult and confusing for the defendant to present different defenses to the different charges; the jury might conclude that because the defendant is guilty of some of the charges, she has a criminal disposition and is guilty of them all; the jury might cumulate all of the evidence and find for guilt on multiple charges where, separately, they wouldn’t find guilt at all; and simply seeing the mountain of charges against the defendant may cause the jury to feel hostility towards her. For this reason, defendants can move to sever charges if they feel that their case will be unfairly prejudiced by the charges brought against them.

However, most cases do not go to trial. A report by the National Association of Criminal Defense Lawyers found that around 97% of federal cases do not go to trial; instead, defendants plead guilty. At the state level, about 94% of defendants take a plea bargain. This means that prosecutors, much more than judges or juries, are ultimately determining people’s sentences. Defendants know that if they do not accept a plea bargain, a prosecutor can bring them to trial on a whole host of charges.

If prosecutors were not able to bring so many charges against defendants, they would not have so much leverage in plea bargain negotiations. We take for granted that prosecutors have this power. However, as Andrew Crespo argues, current joinder rules exist along a spectrum between permissive, giving prosecutors more power, and restrictive, giving prosecutors less power. If legislators passed more restrictive joinder rules, prosecutors would not be able to stack charges against defendants. Prosecutors would then have a less powerful position in plea bargaining.

The current federal joinder rule allows prosecutors to add charges when “the offenses charged … are of the same or similar character, or are based on the same act or transaction, or are connected with or constitute parts of a common scheme or plan.” This is a fairly permissive rule. One way to pare it back and decrease prosecutorial power would be to delete the option of stacking charges that “are of the same or similar character,” only allowing for defendants to be charged simultaneously for crimes arising out of the same incident or common plan. Another more aggressive option would be to limit the number of charges that can arise from a single incident for a defendant, setting a maximum number of charges at three, or even one. Or prosecutors could be prohibited from adding charges that are substantially the same, as in the burglary example above.

Criminal procedure plays a large role in creating an imbalance of power between prosecutors and defendants. Changing the rules can help make the plea bargaining (and trial) process less unfair by forcing prosecutors to choose what they want to charge more carefully. Of course, amending joinder rules is not a panacea. Even if prosecutors could only bring one charge per incident, a reform which would be very difficult to get passed, current sentencing practices are so extreme that prosecutors would still wield outsize leverage over defendants. But any step that can level the playing field at all during plea negotiations must be considered. Rethinking procedural rules like joinder strikes at an important source of prosecutorial power and has the potential to greatly impact plea negotiations and reduce defendants’ sentences.