Investigation: Text in italics describes those parts of the investigation which were unknown to the general public at the time. (a) April 19, 2009 The investigation began. One of the victims claimed, that she had heard someone calling out "Burn gypsies!" Senior politicians, including the Czech prime minister and president, condemned the act, placing it in the context of a more general growth of extremist groups. A special team of fifteen detectives was set up to head up the police investigation. There were three initial working hypotheses: a racially motivated attack, an attack by a money lender to whom the victims were in debt, or a personally motivated revenge attack. Before the attack, one of the perpetrators called a friend, who was at a discothèque. Asked about the call by her companion, the girl answered, "He said they are going on gypsies". A volunteer fireman, who was near the two young women in the discothèque overheard the conversation. On the next day he made the connection between the conversation and the arson attack, and contacted the police. The discotheque witness later faced death threats from right wing extremists, as a result of which he refused to testify in court. However the lead was crucial, because investigators were able to identify and tap suspects' telephones, and so start uncovering the background to the attack. The police made no public reference to this lead. Officially they maintained that they had no direct leads, but were following up on the suspicion that the attack might be part of wider campaign of violence orchestrated by leaders of the Czech extreme right, and not an isolated incident. The fireman's contribution would be revealed only after the end of the investigation