You respond on a residential burglar alarm. You checked the perimeter of the house and nothing looks broken into. You then check the front door of the house by knocking on it first. The door appears ajar and then swings open from the light force of your knock, but no one answers when you yell "police". Should you then go ahead and walk through the house to 'search' for an intruder or simply secure the door back the best way possible? Would this be considered an unlawful search? What is your liability