According to the Fourth Amendment of the U.S. Constitution, the
police can only arrest a person when they have probable cause,
which means that they have to have a good reason to believe
there's been a crime and that the suspect committed it. A judge
will later decide whether or not there was probable cause to
detain the suspect, and if there was not, the detainee will be
released. At the time of arrest, the police must inform the
suspect of his or her constitutional rights, including the
rights to remain silent and to consult an attorney. If the
suspect is charged with the crime, a prosecutor decides whether
to bring criminal charges, and which crime or crimes the suspect
is to be charged with. In felony cases, or crimes for which the
penalty could be one year or more in jail, prosecutors may
enlist the help of a grand jury. In most states, prosecutors
must file charges against a suspect held in custody within 72
hours of arrest, but some states require this even sooner. In
California, for example, a charge