went on their most extensive search yet for sierra lamar closer to home. you can see yellow ribbons have been put up as her family continues to hold out hope for her safe return. at 10:00 a.m. this morning, search and rescue crews, aided by canine, fanned out to look for anything that could lead them to sierra lamar. we ve expanded our search now to a 12-mile radius outside much sierra s mom s house. it will take us to the southern end of the county and to the south end of san jose. reporter: the fourth and largest search effort since the 15-year-old was reported missing since march 16th. 90 law enforcement officials are involved, 30 from sant clara county, others from outside. its search and rescue crew pulled over wherever possible to look nor bridges and through brush for any sign of lamar. something that, you know, we need to remember is that nobody actually saw sierra leave her home. so we can t confirm what she had on, what she was wearing or what time she actuall