california, just outside san diego. 23-year-old freelance camera man greg torkelson is listening to his police scanner. >> something happens. a shooting, a car crash, a house fire, something like that. i respond to it and try to get is the good shots. >> shortly after 5:00 p.m., he hears about a man brandishing a gun inside a residential home. that man is 32-year-old kevin collier. despondent since his wife filed for divorce five days earlier. he had moved out but now came back with a gun. when he discovers alissa is out, he instead shoots and kills their 14-month-old daughter riley and his mother-in-law. >> i had no reason not to be home. i should have been there. >> collier is now holed up in the house. el cajon police have taken up position when greg arrives. >> i saw officers had their guns