( CNN ) -- A California death row inmate has provided maps that led to the remains of two bodies and an abandoned rural well that has yielded 1,000 pieces and fragments of bone , authorities said . Wesley Shermantine , one of two so-called `` Speed Freak Killers , '' was sentenced in 2001 for four homicides , Deputy Les Garcia , public information officer for the San Joaquin Sheriff 's Office , said Tuesday . Authorities now are looking into whether there could be more buried victims . They set up a hotline for relatives of missing persons who may have fallen victim to Shermantine and another man , between the mid-1980s and 2000 , Garcia told CNN . They had received about 50 calls by late Tuesday . Shermantine provided maps and letters to a reporter at the Stockton Record , who then forwarded them to investigators , Garcia said . Searchers , aided by dogs , first went to sites in San Andreas in Calaveras County , he said . One of the pieces of property belonged to the Shermantine family . Human remains were discovered . The remains of Chevelle Wheeler , who disappeared in the 1980s , were tentatively identified , Garcia said . Authorities believe the other victim was Cyndi Vanderheiden . The search for additional victims now is primarily focused on a 19th-century well near Linden , about 30 miles from where the two women 's remains were found , Garcia said . Linden is 55 miles south of Sacramento . `` It is very tedious work , '' he said . Since Thursday , searchers have dug down about 45 feet and have not reached water . They have no idea how many victims may be in the well . `` We are committed to collect all the remains that are humanly possible so that we can bring the loved ones to their families , '' Garcia said . Besides hundreds of pieces of suspected human bone , investigators are unearthing purses , belts , coats , shoes and rings . `` The personal items and the clothing we are finding have been buried for over 20 years , '' he said . Bounty Hunter Leonard Padilla told CNN on Monday that he promised Shermantine $ 33,000 for information leading to the remains of Wheeler and Vanderheiden . About $ 18,000 was for the inmate 's restitution and $ 15,000 was for headstones for Shermantine 's parents ' graves , he said .
Authorities say Calfornia serial killer gave information on body locations . The bodies of two women were found in the same area last year and authorities believe they are linked to the same killer. Wesley Shermantine was sentenced for four murders .