Short answer. Yes, through a third-party complaint. With leave of court, a defending party may file a claim against someone not already a party to the case, for contribution, indemnity, subrogation, or other relief connected to the plaintiff's own claim against them.
What the law says
A third (fourth, etc.)-party complaint is a claim that a defending party may, with leave of court, file against a person not a party to the action, called the third (fourth, etc.)-party defendant, for contribution, indemnity, subrogation or any other relief, in respect of his or her opponent's claim.
Rule 6, Section 11 — Third, (fourth, etc.). Read the full provision →
What a third-party complaint lets a defendant do
A defending party who believes someone outside the case bears real responsibility for the plaintiff's claim can file a third-party complaint against that person, bringing them into the same lawsuit. The remedies available are specific: contribution, indemnity, subrogation, or any other relief, all tied to the plaintiff's own claim against the defending party. It is not a way to raise an unrelated grievance against a third person.
Leave of court is required first
This is not a claim the defending party can simply file on their own initiative — it requires leave of court. The court decides whether bringing the third person into the existing case is appropriate before the third-party complaint may proceed at all, which gives the court a gatekeeping role over whether the case should grow to include this additional party.
Three situations where the court will refuse it
Even after leave is granted, admission of the third-party complaint can still be denied, and the court will instead require a separate action, in three situations: the third-party defendant cannot be located within thirty calendar days from the grant of leave; the complaint raises matters extraneous to the issue in the principal case; or its effect would be to introduce a new and separate controversy into the action. These safeguards keep the original lawsuit from being turned into something unrelated.
Why this matters for someone being sued
Bringing in the person who is truly responsible can let a defendant resolve the whole dispute — the plaintiff's claim and the question of who ultimately pays — in one proceeding, instead of being forced to pay first and separately chase the responsible party afterward. Whether it succeeds depends on how closely the claim against the third party relates to the plaintiff's own claim, since the rule exists to keep related liability together, not to expand the lawsuit into unrelated territory. A defendant considering this route should be ready to explain, when seeking leave, exactly how the third party's fault connects to the claim already being litigated.