By the middle of the fourteenth century, a defendant who had slain a housebreaker might be acquitted by judgment of the court. The same applied where he had slain someone who came to rob him. The courts were not consistent in their treatment of such cases, and it appears that at least until late into the century, acquittal might depend upon clear evidence of self-defence. In this area, the community was ahead of the courts. Trial juries supplied evidence of self-defence where, on the basis of coroner’s inquest testimony there had been neither true self defence nor even clear evidence of housebreaking or attempted theft.
Thomas A. Green, “Societal Concepts of Criminal Liability for Homicide in Mediaeval England” (1972)