from tower to tower. >> signal strength had to be similar within the towers and a poor signal that it would cause the handing off that we saw. >> eventually they found it. the only spot in town that caused the strange pattern of pings. it was at the gordon river, the very spot where spot where anni killed. >> at 9:01 p.m. on march 10th shall the phone was within 100 meters of where we're standing. >> it turned out, of all the people who could have called chris that night, the one who did at 9:01 p.m. was annie's mom veronica. that was because of something annie told her earlier that morning. something about chris. >> he had asked her, what would you do if i asked you to runaway with me? >> runaway. >> he was the first person i'm calling if anything happens. >> which she did. without realizing it, helped misplace chris bag shaw at the scene of the crime, right around the time her daughter was