Mexico Probes Possible Female Vengeance Killer Mexican prosecutors say they are investigating claims that a woman who killed two bus drivers in the northern border city of Ciudad Juarez was seeking revenge for alleged sexual abuse of female passengers. The claims made in an email from the self-styled "bus driver hunter" echoed deeply in a city with a grim history of sexual violence against women aboard buses. Authorities have not verified the authenticity of the email sent to news organizations. But the spokesman for the state prosecutors' office said Monday the vigilante-style claim is being actively investigated. Spokesman Arturo Sandoval says revenge had been considered a possible motive from the start in last week's slayings. The city government also says it will put undercover police aboard some buses and conduct weapons searches to prevent further killings.