The United States is one of the few developed countries in which the death penalty is still legal in certain places, despite it being an inhumane and outdated form of punishment. The practice is also expensive, irreversible and ineffective when it comes to curbing criminal offenses.

Execution proceedings happen in the state of Pennsylvania five times each year — yet the state hasn’t executed an inmate since 1999. Mock executions are routinely performed to ensure that in the...