Tom Sullivan holds a photograph of his son, Alex,  outside Gateway High School in Aurora, Colo., on July 20, 2012, as he pleads with the media to help him find his son. Alex Sullivan was celebrating his 27th birthday by attending midnight premiere of the Batman movie Friday night. A gunman wearing a gas mask set off an unknown gas and fired into the crowded movie theater killing 12 people and injuring at least 50 others, authorities said. (Associated Press)

Photo by: Barry Gutierrez

Tom Sullivan holds a photograph of his son, Alex, outside Gateway High School in Aurora, Colo., on July 20, 2012, as he pleads with the media to help him find his son. Alex Sullivan was celebrating his 27th birthday by attending midnight premiere of the Batman movie Friday night. A gunman wearing a gas mask set off an unknown gas and fired into the crowded movie theater killing 12 people and injuring at least 50 others, authorities said. (Associated Press)