Federal Supreme Court, 27.08.2026, 7B_662/2025
Facts
On January 30, 2022, A.________, while driving under the influence of alcohol and ecstasy, caused an accident on the A1 motorway, injuring two passengers in the other vehicle, C.________ and D.________.
He then fled the scene (Fact A.a).
On April 1, 2022, C.________ and D.________ filed a criminal complaint with the Geneva police (Fact A.a).
On May 10, 2022, unaware of these complaints, the Vaud Public Prosecutor's Office issued an initial penal order convicting A.________ for various Road Traffic Act (LCR) offenses (driving while incapacitated, hit-and-run, etc.), but not for bodily injury (Fact A.b).
Subsequently informed of the complaints, the Vaud Public Prosecutor's Office deemed them to constitute an objection to the initial penal order.
It resumed the investigation and, on September 27, 2023, issued a second penal order, this time also convicting A.________ for negligent bodily injury and increasing the sentence (Facts B.b, B.c).
A.________ filed an objection to this second order.
The proceedings continued to the Vaud Cantonal Court, which, in a judgment dated February 10, 2025, essentially upheld the conviction handed down based on the second penal order.
The Cantonal Court ruled that the initial penal order of May 10, 2022, was void because it had been issued without taking the complainants into account, thereby depriving them of their rights
(Fact B.f, consid. 2.1).
A.________ has filed a criminal appeal with the Federal Supreme Court.
He argues that the first penal order had become final and that the second violated the ne bis in idem principle (the prohibition against being tried twice for the same facts) (Fact C).
Law
The ne bis in idem principle prohibits a person from being prosecuted or punished criminally a second time for acts for which they have already been definitively acquitted or convicted.
A summary penalty order that is not challenged within the 10-day time limit acquires the authority of res judicata and has the effect of a final judgment (art. 354 para. 3 CrimPC) (recital 2.2, 2.4.2).
The absolute nullity of a court decision is an exceptional sanction, reserved for the most serious, manifest, or easily detectable defects (for example, lack of authority).
Simple illegality is not sufficient; it must be challenged through ordinary legal remedies.
In criminal matters, the nullity of a final decision must be admitted with great restraint, due to the importance of legal certainty (recital 2.3).
The fact that an authority renders a decision without the participation of a directly affected person may be a ground for nullity, but only if the law mandatorily requires that person's participation (recital 2.3).
Revision (art. 410 CrimPC) is an extraordinary legal remedy that allows for a final judgment to be reopened, particularly in the presence of new and significant facts or evidence that already existed at the time of the initial judgment but were unknown to the judge (recital 2.2).
Application to the specific case
The central question is whether the Cantonal Court was correct in considering that the first summary penalty order of May 10, 2022, was void (recital 2).
The Federal Supreme Court answers in the negative.
The fact that the Public Prosecutor's Office was unaware of the complaints from C.________ and D.________ does not constitute a defect sufficiently serious to result in the absolute nullity of the first order (recital 2.4).
Contrary to the ruling of the Cantonal Court, the complainants were not deprived of all legal protection.
The participation of the injured party in criminal proceedings is not an obligation imposed by law; they remain free to assert their civil claims before a civil judge (recital 2.4.1).
Furthermore, the complainants had other legal remedies available to them.
The summary penalty order of May 10, 2022, should have been served upon them.
The 10-day time limit for filing an objection therefore only began to run for them from the date of effective notification, August 8, 2022.
D.________ stated that they were maintaining their complaint on August 12, 2022, which was within the time limit, and could therefore be interpreted as a valid objection (recital 2.4.2).
Even if the order had become final, the complainants could have requested a revision under Art. 410 of the Swiss Criminal Procedure Code, citing the existence of their complaints as a significant new fact capable of justifying a more severe conviction (recital 2.4.2).
Since legal remedies (objection, revision) existed to rectify the situation, there was no need to resort to the exceptional sanction of nullity.
By ruling that the first order was void, the Cantonal Court violated federal law (recitals 2.4.3, 2.5).
Outcome
The Federal Supreme Court allows the appeal (Operative part 1).
It sets aside the judgment of the Criminal Court of Appeal and remands the case for a new decision.
The Cantonal Court must examine whether D.________'s letter of August 12, 2022, constitutes a valid objection to the first penal order.
Based on this analysis, it must determine whether the first order became final and, if so, whether the second proceeding violated the ne bis in idem principle (Operative part 1, recital 2.5).
No court costs are charged, and an indemnity of 1,500 CHF is awarded to the appellant, to be paid by the Canton of Vaud (Operative parts 2 and 3).