Sergeant McGuigan argues that Maryland law never clearly defines "penknife." As a result, McGuigan says that a reasonable officer interpreting the penknife exception must rely on the common understanding of a penknife as a small pocketknife and that Sorrells knife was arguably not a small pocketknife.
McGuigan is wrong. While the concealed weapons statute does not define "penknife," the highest court in Maryland defined it back in 1978.