36 Human Rights in Counter-Terrorism Investigations About half an hour later, all three men leave together and drive away in Y’s car. The surveillance team follows them, but one of the team stays behind and, using a skeleton key, enters X’s home and places a listening device in the room where the three men had been, believing that this will be useful during any future meetings the men may have. Question: Does the police surveillance operation unlawfully interfere with the suspects’ right to private and family life? The use of registered informants is a police tool frequently necessary in cases of serious crimes. Informants, when tasked by the police, frequently invade the privacy of people they are asked to collect information about. Therefore, the use of informants is strictly regulated and supervised. Their use is only permitted in cases of serious crimes – sometimes described in national criminal procedure codes – and with carefully selected and trained informant handlers. Another important good practice when using informants is a strict separation between the informant handler and the investigation. The decision to use an informant requires either the permission of a specially selected senior officer in dangerous protection cases or the permission of a judge in criminal cases. Taking information from members of the public about suspicious behaviour of neighbors is, at most, a low-level invasion of their privacy. This is basic police work and does not require special permission. Also, discreetly asking questions of neighbours and other members of the public can be considered basic police work and open intelligence gathering for which no special permission is needed. The police officer in uniform and on his beat following X for a short time is also a low-level infringement of X´s privacy for which no special permission is needed. The office-based identification of suspects can interfere with the privacy of those under scrutiny. It can only respect human rights when it is done by agents of a specialized unit. Results must be presented to a senior officer in charge or a prosecutor, who decides whether or not the material leads to an investigation. The initial surveillance of the two men and their meeting outside the bank is the start of the long-term activity, including technical support. The seriousness of the suspected crime they are believed to be plotting justifies the action. However, domestic legislation should require judicial authorization for long-term surveillance with technical support.