The Federal Court has ruled that authorities are allowed to tap third-party telephone connections that are called by a wanted person, in a decision that may set the agenda for proposed changes of national intelligence legislation.
The judges in Lausanne said that Zurich prosecutors may tap the wires of a friend of a suspected robber in order to track him down. The supreme court argued that alleged offenders should not be allowed to escape surveillance measures by frequently changing phones.
The ruling may be a prelude to changes to the federal law on internal security, which the defence ministry is expected to table by the end of the year. The proposed modifications will deal with questions on how to expand tracing methods and preventive measures, including wiretapping.
The decision came after an appeal from the Zurich cantonal prosecutor’s office against a cantonal court ruling.
The prosecutors’ office conducted in 2010 a criminal investigation against a man who was suspected of having planned and prepared robberies. They did not know the whereabouts of the person and the telephone connections he used. The identity of his girlfriend, who was not subject to investigations herself, was known though.
The prosecutors’ office filed a request to keep taps on her telephone for a few months to trace the suspect. The cantonal court refused permission.
The federal court specified that investigators are only allowed to tap third-party connections if there is evidence that the target person is calling the number on a regular basis. Surveillance must be stopped once the number of the suspected person is known, because investigators may then tap the suspect’s phone directly.
Prosecutors also do not have the right to record conversations where the suspect is not taking part, the judges said.
The case is legally still ambiguous, according to the Lausanne judges. Current law only permits the surveillance of third-party phone lines a suspect is calling from. The prosecutors argued that the law should also apply to cases where a wanted person is frequently calling a third-party connection.
The defence ministry is working again on changes to the federal law after an earlier version was rejected by parliament in 2009, saying that it went too far. The modification proposed at the time would have granted law enforcement services for example the right to preventively observe private apartments, telephones, mail, computers or suspected hotel guests.