On 2 October the RPF leader Fred Rwigyema was shot in the head and killed. The exact circumstances of Rwigyema's death are disputed; the official line of Kagame's government, and the version mentioned by historian Gérard Prunier in his 1995 book on the subject, was that Rwigyema was killed by a stray bullet. In his 2009 book "Africa's World War", Prunier says Rwigyema was killed by his subcommander Peter Bayingana, following an argument over tactics. According to this account, Rwigyema was conscious of the need to move slowly and attempt to win over the Hutu in Rwanda before assaulting Kigali, whereas Bayingana and fellow subcommander Chris Bunyenyezi wished to strike hard and fast, to achieve power as soon as possible. The argument boiled over, causing Bayingana to shoot Rwigyema dead. Another senior RPF officer, Stephen Nduguta, witnessed this shooting and informed President Museveni; Museveni sent his brother Salim Saleh to investigate, and Saleh ordered Bayingana's and Bunyenyezi's arrests and eventual executions.