Facts
The Public Prosecutor's Office for Economic Crime and Organised Crime of the Canton of Thurgau conducted criminal investigation proceedings against X. on suspicion of misappropriation and money laundering. On 1 September 2010, the Cantonal Investigating Magistrate's Office had the accused's residence searched. Various files were seized and, at the request of the accused, sealed.
On 21/22 September 2010, the Investigating Magistrate's Office and the accused jointly sorted out those files that were to remain sealed, those released for search, and those not relevant to the investigation. On 8 October 2010, the Investigating Magistrate's Office applied for the unsealing of the records still sealed.
The unsealing proceedings were transferred on 4 January 2011 by the President of the Indictment Chamber to the Compulsory Measures Court of the Canton of Thurgau, due to the entry into force of the CrimPC. On 3 March 2011, the Court ordered continued seizure. On 24 August 2011, a triage was carried out in the presence of the parties, and by decision of 16 September 2011 the Compulsory Measures Court authorised the unsealing of part of the files. According to the decision, attorney files of a co-accused attorney were also released for search. The accused was further charged a decision fee of CHF 10,000.
The accused lodged a criminal law appeal with the Federal Supreme Court. She requested the annulment of the unsealing decision and the interlocutory order, the exclusion of further documents from unsealing (items 1.2-1.7 of the operative part), and the annulment of the cost imposition. She essentially complained of a violation of attorney-client professional secrecy, a lack of connection to the offence, and an unlawful cost imposition under Art. 426 CrimPC.
Considerations
The Federal Supreme Court first examined the extent to which the appellant may invoke attorney-client professional secrecy as an obstacle to unsealing (Art. 171 para. 1, Art. 248 para. 1, Art. 264 para. 1 lit. a and c CrimPC). An absolute prohibition on seizure and unsealing applies to documents from the communication of the accused person with their defence. Correspondence with attorneys who are not themselves accused, by contrast, is protected provided there is no co-accusation in the same factual context.
Correspondence with a co-accused attorney and notary, as well as files that did not concern protected attorney activity, could be released for search. An attorney who is himself co-accused in the matter cannot withdraw investigation-relevant evidence from the reach of the prosecuting authorities by substituting office partners or foreign correspondent attorneys. This would contradict the meaning and purpose of Art. 264 para. 1 lit. c CrimPC. A different outcome would apply to independent mandate relationships with non-accused attorneys or in subject areas not relevant to the investigation, but the appellant did not substantiate this concretely.
On the material connection, the Federal Supreme Court held that the unsealing judge must sort out objectively irrelevant items. The Public Prosecutor's Office must explain in the unsealing application how the sealed items may be relevant to the proceedings. The affected person, for their part, has the obligation to assist the Compulsory Measures Court in the review and to identify those items that are subject to confidentiality or obviously lack any connection to the matter (Art. 248 CrimPC; BGE 137 IV 189). This applies particularly where very large volumes of data are involved. A blanket objection is not sufficient.
In the present case, in which the appellant is herself accused, no special restraint was required under Art. 197 para. 2 CrimPC. She had ample opportunity in…