CHICAGO --Chicago police say they've solved the case of a pregnant mother gunned down in front of her own children on Halloween. Leticia Barrera was four months pregnant and had just returned from a night of trick or treating. Officers say she was caught in the middle of gang violence. This was a very troubling case for the neighborhood and for police. It happened in the Back of the Woods neighborhood. Police say they have worked diligently to track the suspect down. They have identified him as 18-year-old Orlando Avila. They say he's an alleged gang member who was involved in a dispute with rival gang members on Halloween night last October. Police say he fired the shot that killed 32-year-old Barrera as she was with her three children just outside the gate to their home. Witnesses and friends say that Barrera and other mothers had purposely gone to a well-lit business district nearby where they thought they would be safe. Police do say that she was certainly not the intended target. They also say that they got a tremendous amount of help in this investigation from nearby surveillance cameras. "Area One detectives and night district officers reviewed the video and were able to locate the witnesses with the assistance from the community. Several witnesses provided solid investigative leads that helped identify the offender," said one officer. Barrera's three young children were with her, still in their Halloween costumes, and witnessed the shooting. Her husband and she both are from Mexico. She has lived here for about seven years. Avila is facing one count of first-degree murder and two other counts of attempted murder. Police also say that there is still one other suspect out there that they are still looking for.