A gunman killed three police officers and wounded three others on Sunday in Baton Rouge, Louisiana, where tensions have been high since the fatal shooting of CD vendor Alton Sterling outside a convenience store two weeks ago. After the officers died, the mother of Sterling’s son Cameron, Quinyetta McMillon, said the family “rejects violence of any kind directed at members of law enforcement or citizens.” President Obama condemned the attack as “cowardly and reprehensible.” Police shot and killed the alleged gunman — Gavin Eugene Long, a 29-year-old ex-Marine who served in Iraq — and searched for two other “persons of interest.”