This week marks the 25th anniversary of Wyoming's last execution.

Jan. 22, 1992, convicted murderer Mark Hopkinson received a lethal injection.

Hopkinson was the only person Wyoming has put to death in the last 50 years and was the only man executed by injection.

Prior to Hopkinson, Wyoming's most recent execution was in 1965, when Andrew Pixley was sent to the gas chamber for killing two young girls.

Since Wyoming became a state in 1890, it has carried out the death penalty 18 times; 13 by hanging and four by gas chamber, which was introduced in 1937.  Wyoming has never had an electric chair.

Prior to statehood, the Territory of Wyoming legally executed seven men, all by hanging. In those days, many more outlaws were hung or shot by vigilantes and mobs.

Along with Hopkinson, the most famous man ever executed in Wyoming was a bounty hunter and local legend Tom Horn, who was hung following his controversial conviction for murder in 1903.

In addition to the 25 official executions carried out by the state or territory, one federal prisoner was executed in Wyoming.

In 1945, Henry Ruhl was convicted of murder on a government reservation. His sentence was carried out at the Wyoming State Penitentiary in Rawlins under an executive order from President Harry Truman.

In 1972, the United States Supreme Court outlawed the most forms of the death penalty in Furman vs. Georgia. In 1977, Wyoming officially established new provisions for capital punishment. Currently, there are no prisoners on death row in the state.