Drug prohibition feeds negative stereotypes of those who use drugs, making them targets for many kinds of abuse. A former fire chief in Brazil, Jorge Luiz Thais Martins, is suspected of killing at least eight drug users in the neighborhood where his son was shot dead in a robbery attempt. "Police are investigating the possibility the crimes were committed as vengeance," said Giovani Santos, a spokesman for the public safety department. He said Martins is being investigated in part because a drug user who survived a recent attempted killing identified Martins as the shooter.