Thomas Creech, 73, a serial murderer who spent more than 50 years on death row, was scheduled to be executed by lethal injection. Ivan Cantu, 50, sentenced to death in 2000 and whose fate attracted the attention of celebrities, is awaiting execution Wednesday evening in Texas.

Actor Martin Sheen urged on Instagram to sign the online petition, which has already collected more than 150,000 signatures, to ask Texas Governor, conservative Greg Abbott, to stay the execution. According to a recent poll by the Gallup Institute, a majority of Americans believe that capital punishment is not fairly applied in the United States.