Admissibility of illegally obtained private evidence in road traffic matters and weighing of interests under Art. 141 para. 2 CrimPC and the FADP

Facts

The accused (A.) on 18 May 2018 at around 07:55 in Lausanne, exceeded the speed limit (55 km/h) and drove dangerously past a moped rider (B.), abusively using his horn. During the manoeuvre, A. abruptly swerved to the right, forcing B. to brake sharply and hit the car to attract attention. B. filmed the incident with a GoPro camera mounted on his handlebar.

The Police Court of the Lausanne district convicted A. of simple and serious violations of road traffic regulations (Art. 90 paras. 1 and 2 RTA) to a fine of 300 francs per day for 30 days and a fine of 3,000 francs. The Criminal Appeals Court of the Vaud Cantonal Court upheld this judgment on 19 September 2019.

A. filed an appeal in criminal matters before the Federal Supreme Court, contesting the admissibility of the video recording, which he claimed was obtained illegally. He requested acquittal or, in the alternative, a reduction of the penalties. The Central Public Prosecutor's Office of the Canton of Vaud argued for dismissal of the appeal.

Considerations

The Federal Supreme Court first recalled that Art. 141 para. 2 CrimPC governs the admissibility of evidence illegally obtained by private individuals. According to case law, such evidence is admissible only if: (1) it could have been lawfully obtained by the criminal authorities, and (2) a weighing of the interests at stake favours its admissibility, particularly to clarify serious offences (ATF 146 IV 226 para. 2.1; 6B_53/2020).

The Court then examined whether the video recording constituted an unlawful infringement of the accused's personality rights under the FADP. The GoPro camera, mounted on the moped's handlebar, recorded continuously without discrimination or recognition, capturing notably the accused's licence plate. This collection of personal data was deemed unlawful as it violated the principles of transparency and proportionality under Art. 4 FADP, without any justifying ground under Art. 13 FADP (consent, overriding interest, or law). Justifying grounds are narrowly construed, especially for systematic recordings such as those from dashcams or onboard cameras (ATF 146 IV 226 paras. 3.2 and 3.3).

The Court then applied the weighing of interests under Art. 141 para. 2 CrimPC. Although the offences alleged (traffic rule violations) are not abstractly considered serious, their concrete gravity was assessed. The dangerous overtaking, though without accident or injury, did not reach the required level of gravity to justify the use of illegally obtained evidence. The…