second stage: Investigation
interrogation
The questioning of a prisoner was essential to every case, as it served not only to unearth information relevant to the offence but also as an opportunity to acquire information about other offenders. Torture existed as a means of ‘loosening up’ uncooperative suspects. It is widely considered that torture by the Gestapo often yielded imperfect results but was easier than relying on detective work.
Monitoring
Where necessary Gestapo officers may open a case file on an individual suspected of an offence, or denounced, but rather than bringing the suspect in for questioning decide to monitor and follow the individual. Monitoring for further information allowed the Gestapo to construct a better understanding of a opposition network before trying to infiltrate it or establishing a special task unit.