NEW : Police say they ' ve received four calls -- three on Tuesday . A fourth car near mobile home park is searched for clues . A dozen agencies are involved in the search . Sandra Cantu played with a friend on Wednesday , headed for a second friend 's house . It 's not clear whether she ever got to the second house , family says .
NEW : Police say they ' ve received four calls -- three on Tuesday . A fourth car near mobile home park is searched for clues . Sandra Cantu played with a friend on Wednesday , headed for a second friend 's house . It 's not clear whether she ever got to the second house , family says .