Legal Definitions - Mandatory Joinder

Mandatory Joinder refers to a legal principle that requires certain individuals or claims to be included in a lawsuit for it to proceed fairly and effectively. This ensures that all necessary parties are present, allowing the court to issue a comprehensive decision and prevent future disputes or injustice.

In civil lawsuits, mandatory joinder applies when a person who wasn't originally part of the case is deemed "indispensable." This means their presence is absolutely necessary for one of several reasons:

• The court cannot provide a complete and fair resolution to the existing parties without them.
• The absent person has a significant legal interest in the case that would be harmed or unprotected if they were left out.
• Leaving them out could expose existing parties to the risk of multiple lawsuits over the same issue.

If such an indispensable party cannot be included (perhaps due to issues with the court's authority over them or other practical reasons), the court must then decide whether it can still fairly resolve the case without them, or if the entire lawsuit must be dismissed.

In criminal cases, mandatory joinder typically means that all known criminal charges against a defendant that arise from the same incident or series of related incidents must be brought together in a single prosecution. If the prosecution fails to include a known charge that should have been joined, they generally cannot pursue that specific charge in a separate trial later. This rule helps ensure judicial efficiency and protects defendants from being repeatedly prosecuted for offenses stemming from the same events.

Examples of Mandatory Joinder:

• Civil Case - Property Dispute:

  Imagine two neighbors, Sarah and Tom, are involved in a lawsuit disputing the exact boundary line between their properties. However, a third neighbor, Maria, owns the property directly adjacent to both Sarah and Tom, and the disputed boundary line also affects her property's dimensions and access to a shared easement. In this scenario, Maria would be considered an indispensable party. The court cannot fully resolve the boundary dispute between Sarah and Tom without also impacting Maria's property rights. If Maria isn't included, any judgment might be incomplete, unfair to Maria, or lead to a new lawsuit involving Maria later. Therefore, the court would likely require Maria to be joined in the lawsuit under mandatory joinder rules.

• Civil Case - Trust Fund Litigation:

  Consider a situation where one beneficiary of a family trust, named Alex, sues the trustee, Brenda, alleging that Brenda mismanaged the trust funds. However, the trust has three other beneficiaries: Carol, David, and Emily. Carol, David, and Emily are all indispensable parties. Any decision about the trust's management and the distribution of funds would directly impact their financial interests as beneficiaries. The court cannot provide complete relief or adequately protect the interests of all beneficiaries without their participation. If they are not joined, Brenda could face multiple lawsuits from each beneficiary, or Alex might receive a judgment that unfairly diminishes the shares of the others.

• Criminal Case - Multiple Offenses from One Event:

  Suppose a person, Mark, is arrested after a single incident where he broke into a store, stole merchandise, and then assaulted a security guard while fleeing. The prosecutor is aware of all these potential charges: burglary, grand theft, and assault. Under mandatory joinder rules in many jurisdictions, the prosecutor would be required to bring all these known charges against Mark in a single criminal case. If the prosecutor initially only charges Mark with grand theft, and then later tries to bring a separate charge for burglary or assault based on the same incident, the court might dismiss the later charges because they should have been joined with the others. This prevents the state from repeatedly prosecuting Mark for different aspects of the same criminal event.