STAMFORD — Police are searching for clues in what police said were unrelated shootings over Memorial Day weekend that left two teens with gunshot wounds and another person injured. While Stamford officers were responding to reports of gunfire at the hotel, officials said a 16-year-old from the West Side arrived at Stamford Hospital with a bullet wound in his shoulder. Later that day, at around 9 p.m., a 19-year-old from the West Side showed up at Stamford Hospital with bullet wounds in his shoulder and stomach, injuries police described as serious but not life-threatening. Police are reviewing hotel security footage they hope will help them identify the person who witnesses say fired four shots.