Urdiales was born in 1964 in Chicago and served in the Marine Corps, stationed for periods in southern California.
Between 1986 and 1996 he killed eight women, five in Illinois and three in California, most of them working as prostitutes. He stabbed or shot them and left the bodies in remote ground. He was arrested on April 23, 1997.
He was tried in Illinois first, convicted, and sentenced to death on September 3, 2002. On January 10, 2003 Governor George Ryan commuted every death sentence in Illinois, including his, to life imprisonment without parole.
California then sought him. He was extradited in 2011, tried in Orange County for the three killings there, convicted in 2018 and sentenced to death a second time.
On November 4, 2018, weeks after that sentence, he was found hanged in his cell at San Quentin.
His is the clearest example in this archive of the effect of the Illinois commutation on a single prisoner: sentenced to death in one state, spared by a blanket act of executive clemency there, and condemned again in another for the same series. He died in custody before either sentence could be carried out, at a time when California had not executed anyone since 2006.