>> all sex offenders on parole will have an anklet, a gps monitor. >> reporter: she asked where any of those here where jerree placed her last phone call or here where she wound up with a dumpster. you find the same locations, you are getting somewhere? >> mm-hmm. >> reporter: she ran the search. what were the chances she got a hit in both locations? she called detective trapp. >> there's only one person. she says, i know him. i says, who? his name is frank canno, he's a sex offender. >> reporter: he pleaded guilty to committing a lewd act on a minor. now, did his monitor put him near the places those other three women, according to phone records, made their last calls? quinna, josephine and martha? one by one the detective got the coordinates.