Searchers found no signs Monday of the bodies of a 4-year-old Patterson boy and his kidnapper.
Authorities say Jose Esteban Rodriguez drove into the Delta-Mendota Canal near Patterson after taking Juliani Cardenas on Jan. 18.
Rodriguez is a former boyfriend of the boy's mother. Rodriguez's car was pulled from the canal Friday.
A California Highway Patrol aircraft is flying over the canal, weather permitting.
Law enforcement officers are checking the canal as far south as Fresno County.