( CNN ) -- Police and the mother of a 4-year-old California boy clung to hope Thursday for the child 's safety , days after a man allegedly snatched the pre-schooler from his grandmother 's arms then took off . An Amber Alert was issued for Juliani Cardenas , who authorities say was abducted by Jose Esteban Rodriguez in the northern California town of Patterson . `` He ( Rodriguez ) wanted to be with my son , '' Tabitha Cardenas told reporters Thursday , adding that she had broken up with Rodriguez four or five months ago . `` He wanted to be with my son so bad that he took it to the extreme . '' Yet authorities feared the worst , after a witness reported seeing a car matching that of the alleged kidnapper plunge into the Delta-Mendota Canal . But they were not able to locate the vehicle during searches Thursday . `` We believe the suspect drove the car into the canal , with little Juliani inside , '' Stanislaus County Sheriff Adam Christianson told HLN 's Nancy Grace . `` But so far , we have n't been able to locate the car . '' Christianson said that the search will resume Friday , with help from the neighboring Merced County sheriff 's department , using side-scanning sonar . The sheriff , though , also held out hope that the witness may have been mistaken -- and Juliani , in fact , never went underwater . `` There 's still hope that we 're going to be able to find Juliani alive , '' he said . In an emotional press conference Thursday , the boy 's mother said she believes Rodriguez is troubled -- claiming he told her that he sometimes `` hears voices '' and that he had been abusive when they were dating -- but she did not think he would drown her son or consciously put him in danger . Rodriguez is not the boy 's biological father . `` He 's scared , Jose 's scared -- I know he is , '' said Cardenas . `` He probably does n't know what to do . '' The suspect had come to Cardenas ' house early Tuesday morning , according to the boy 's mother , leaving after she told him to leave because Juliani was asleep and had a cold . The boy 's school later called Tabitha Cardenas after Rodriguez had gone there asking to spend time with the boy . In the late afternoon , Cardenas got a call from her frantic mother , who claimed that the Rodriguez had again come by and , despite her struggle , had taken the boy from the grandmother 's arms . Cardenas said that her mother told her that the suspect then flashed an obscene gesture , laughed and got into his 2003 silver Toyota Corolla , which he had left running . The boy , Juliani , is 3 feet , 6 inches tall , weighs 40 pounds and has brown eyes and black hair , according to the Amber Alert . He was wearing dark pants and a light blue shirt at the time of his abduction . Rodriguez , 27 , is described in the same alert as being a Hispanic male , about 180 pounds and 5 feet , 9 inches tall . Tabitha Cardenas , who broke down several times while addressing reporters , said she especially was worried that her son was not getting enough water or food . She issued an urgent plea to Rodriguez , who she said took their break-up hard but stayed in contact , to drop off her son at a hospital or fire department . `` Please , I need him home , '' she said . `` I know he 's telling you that he 's missing me . You need to bring him home . ''
An Amber Alert has been issued for Jose Rodriguez , Friday , of California , Patterson . Police say he was abducted by Juliani Cardenas , the ex-boyfriend of the boy 's mother . The boy 's grandmother says the man took the boy from her arms then fled . Police are searching a canal after a tip that the kidnapper drove his car into it .