Multiple police agencies were searching the area Saturday night for a suspect in the fatal shooting of a CN Railway security guard in Harvey.The incident began about 7 p.m. when the suspect allegedly stole a vehicle. The victim contacted Harvey police and in another car pursued the stolen vehicle, according to news conference video posted on an ABC7 News Facebook page. Harvey police spokesman Sean Howard said the suspect crashed the stolen vehicle into the viaduct at 159th Street and Park Avenue, ran onto the tracks and encountered the CN security guard.The guard was shot . . .