In Pennsylvania, and across the United States, anyone who is charged with a crime have rights that are guaranteed by the U.S. Constitution. A group of these rights are known as "due process" rights, which seek to ensure that criminal defendants are treated as fairly and consistently as possible as they navigate the criminal justice system. When someone charged with a crime hires a criminal defense attorney, part of what the lawyer does is to ensure that the client's due process rights have not been violated.
The due process rights with which most folks are acquainted - from television, movies, and other popular media - are often called Miranda rights. When you see a law enforcement officer make an arrest and inform the arrestee that they have "right to remain silent," etc., these are the Miranda rights. The name comes from the 1966 landmark Supreme Court decision in Miranda v. Arizona.
Citizens have always been protected by the rights enumerated in a Miranda advisory. They derive from the Fifth Amendment of the Constitution. However, prior to Miranda, defendants were not always aware of these rights and law enforcement was not always eager let the defendants know what they were, either. This was the crux of the Miranda decision.
Now, anyone in the custody of law enforcement must be informed of certain Fifth Amendment rights prior to being questioned. Fans of police dramas can likely recite them from memory, but for those who cannot, these are the rights a defendant has when in police custody: The right to remain silent, because anything a defendant says can and will be used against them in court; the right to an attorney; and the right to have an attorney appointed if a defendant cannot afford one.
Anyone arrested by law enforcement should know these rights. More importantly, they should always take advantage of them. Say nothing to law enforcement, and when given the opportunity, call a seasoned criminal defense lawyer.
Source: FindLaw.com, "'Miranda Rights' and the Fifth Amendment," accessed Feb. 27, 2018