One good example is these Magna Carta sections, from http://www.britannia.com/history/docs/magna2.html
39. No freeman shall be taken, or imprisoned, or disseized, or outlawed, or exiled, or in any way harmed--nor will we go upon or send upon him--save by the lawful judgment of his peers or by the law of the land.
40. To none will we sell, to none deny or delay, right or justice.
That phrase "the law of the land" is what the Americans call "due process of law". People have rights to privacy against the government that have historical roots in Magna Carta, and some have even older roots.
For most of its history, California Penal Code 836 stated:
836. (a) A peace officer may arrest a person in obedience to a
warrant, or, pursuant to the authority granted to him or her by
Chapter 4.5 (commencing with Section 830) of Title 3 of Part 2,
without a warrant, may arrest a person whenever any of the following
(1) The officer has probable cause
to believe that the person to
be arrested has committed a public offense in the officer's presence.
(2) The person arrested has committed a felony, although not in
the officer's presence.
(3) The officer has probable cause to believe that the person to
be arrested has committed a felony, whether or not a felony, in fact,
has been committed.
The law of the land requires that a person not be arrested for a misdemeanor
not committed in the officer's prersence, and that was the law of the land in 1215 in Britain as it is today in almost all common law jurisdictions. This is a substantive due process right, not to be arrested for a misdemeanor based on hearsay to an officer.
Does this give you enough to work with?