Abstract: An improved double-locking mechanism for handcuffs is disclosed. In the preferred embodiments, a standard pawl and multi-piece slide-bolt assembly have been modified to prevent premature sliding of the bolt into its "double-locking" position, and to prevent dislodging of the bolt back into its "non-locking" position. The unique slide bolt, or the nearby lock casing, is angularly offset to create a fulcrum. The bolt also has an underlying tab that is designed to rest in either of two side-by-side locator notches atop a cuff's pawl. One notch firmly locates the bolt in a double-locking position, while the other notch normally keeps it in a non-locking position. To shift the bolt into its double-locking position, an authorized user presses any suitable actuator (e.g., the tiny end of a handcuff key or a ball-point pen end) against an exposed inclined end of the bolt. This pivots the bolt about the fulcrum and against the casing, so that it lifts the tab out of the non-locking locator notch.