Use a bump key when you lock yourself out of your own home, or when you need to gain access to a friend's home during a crisis. Lock bumping ordinarily leaves no signs of damage or tampering. When you bump a lock, the energy from the strike moves through the key to the bottom pins.
This is classic criminology, tracing its origins to Cesare Beccaria and working to the most modern theories of individual and group behavior. When the word is mentioned in a law enforcement agency, another image appears. Practical criminology focuses on the common actions of lawbreakers. Police officers are not as concerned with theories of criminality as they are with the practical aspects of criminal behavior.
Most policy-making in criminal justice is based on criminological theory, whether the people making those policies know it or not. In fact, most of the failed policies (what doesn't work) in criminal justice are due to misinterpretation, partial implementation, or ignorance of criminological theory. Much time and money could be saved if only policymakers had a thorough understanding of criminological theory.