Hue and Cry:
1) The requirement of all members of a village to pursue a criminal with horn and voice. It is a duty of any person discovering a felony to raise the hue and cry and his neighbors are bound to assist him in pursuit and capture of the offender.
(MEDIEV-L. Medieval Terms)

2) Outcry alerting others to pursue a criminal.
(Bennett, Judith M. Women in the Medieval English Countryside, 234)

3) Noisy pursuit of criminals, as a legal duty falling upon local communities.
(Frame, Robin. Colonial Ireland, 1169-1369, 144)

4) Criminal apprehension system by which all within earshot were required to give chase to the malefactor.
(Gies, Frances and Joseph. Life in a Medieval Village, 245)

A medieval glossary that I found fun to browse:
http://www.netserf.org/Glossary/h.cfm