forensic evidence from susan hamilton's murder, homicide investigators asked blood spatter expert ross gardner for his opinion. this case is like many in the sense that what the suspect said is ultimately going to be tested against the crime scene. >> when emergency workers arrived, dr. hamilton was covered in his wife's blood. >> dr. hamilton's presence at the crime scene, the fact that he's bloody is completely expected. he has come home and found his wife dead. he's cradled her, taken action. >> but not all the blood on dr. hamilton's shirt could be explained away. >> dr. hamilton's claims presented some major contradictions. i don't expect to find spatter. the spatter i observed were present on the front of his shirt, below his neck, on both sleeves at the cuff, and this suggested that his arms and his body had been in close proximity to a spatter event. >> on dr. hamilton's shoes were tiny blood droplets, almost invisible to the naked eye. these were suspicious, not only the shape, but the angle at which the blood landed on the shoes. >> there was some coming down on the toe from above 40