 A high-ranking member of a well-known gang in New York has pled guilty to charges involving multiple notorious killings. Details from CBS's Matt Piper. Alexei Saenz is a leader of the MS-13 gang on New York's Long Island. He's now pleaded guilty to racketeering and firearms charges in a case involving eight murders. In one case, prosecutors say the 29-year-old and his brother hunted two teenage girls down in 2016 and attacked them with machetes and beat them with baseball bats.