An arrest simply means a police officer, federal agent, or judge believes probable cause exists that a person committed a crime.
Criminal defense lawyers may also help clients before charges have been filed by a prosecuting attorney: this is done when someone believes he or she is being investigated.
A considerable aspect of this work requires the US criminal defense lawyer to have a clear understanding of the United States Constitution, and specifically the Fourth Amendment against unlawful searches and seizures.
It guarantees a defendant the opportunity to confront and cross-examine witnesses, in addition to the right to be represented by counsel.
Accordingly, a criminal defense lawyer often spends a considerable amount of time reviewing all documentation to determine if the case can be won on constitutional grounds due to illegal conduct by the government.
Many states have "wobblers", which refers to criminal activity that is charged as a felony, but has a possibility of being reduced to a misdemeanor.
To become a criminal defense lawyer, a person will typically complete their undergraduate degree, and then attend and graduate from a law school.
In the United Kingdom, criminal defense lawyers require an undergraduate law degree and authorisation by the Solicitors Regulation Authority.