The GN has a Criminal Investigative Unit that includes specialized units and officers trained in sophisticated evidence collection techniques and forensic sciences. Stolen vehicles are recovered by crossing broad surveillance data on public places with registration and description information contained in the national stolen vehicle file. Police officers systematically visit the site of burglaries and theft offenses, and evidence collection primarily involves sketches and photographs. Police officers are also responsible for obtaining and circulating information, obtaining confession from suspects, and writing up case files. Issues in police investigations of theft and burglary are examined with respect to functional specialization, multiple tasks, large caseloads, and cooperation between the GN and local police.