When law enforcement officials suspect criminal activity in any context, it is common for a criminal investigation to be initiated. This means that effort is made to gather all relevant information relating to the crime. In order to maintain the integrity of the investigation, it is vital that all evidence is maintained and preserved in its original state.
Studies have found that eyewitnesses have a tendency to make mistakes after violent crimes. They give accounts of the event that don't reflect what really happened. They think that they remember things correctly when they have forgotten crucial details or gotten things wrong. They make mistakes that put innocent people behind bars.
On Sept. 6, 2018, a female police officer with the Dallas Police Department shot and killed an unarmed man. She stated that she thought the man was burglarizing her apartment, but the man was actually in his own apartment. She was charged with murder and fired from the police department.