Original: Most constables in modern jurisdictions are law enforcement officers ; in the United Kingdom , Commonwealth of Nations and some European countries , a constable is the lowest rank of police officer ( it is also , when preceded by the term ` sworn ' , used to describe any police officer with arrest and other powers ) , while in the United States a constable is generally an elected peace officer with lesser jurisdiction than a sheriff .
Simplified: In the United Kingdom , Commonwealth of Nations and some European countries , a constable is the lowest rank of police officer . In the United States a constable is usually an elected peace officer , with less powers than a sheriff .