Police say this cruiser caught fire when a round fired from an assault rifle struck a gas line.MIAMI GARDENS, Fla. -- Police say a gunman with an assault rifle opened fire on a Miami-Dade County police officer around 2 a.m. Sunday, striking her twice and setting her cruiser ablaze. The officer is expected to be OK. It's not known how many rounds the gunman fired, but one of them hit the police cruiser's gas line, setting it on fire. Police are looking for the gunman. They say they know his name, but are not releasing it to the public. "Somebody...