With a fatal dose of pentobarbital, Kimberly McCarthy became the 500th prison inmate to be killed in Texas since the state reinstituted the death penalty in 1982.

Officials at the so-called Walls Unit prison in Huntsville, Texas, 70 miles north of Houston, pronounced the African-American woman dead at 6:37 p.m. local time. Texas has an average of 16 executions a year, making it America’s most active execution chamber.

McCarthy, who was denied her final appeal last year, was sentenced to death for the 1997 murder of her neighbor Dorothy Booth, a 71-year-old retired college professor. McCarthy robbed Booth for money to feed her addiction to crack cocaine in a brutal crime that involved beating the old woman with a candelabrum, stabbing her to death with a kitchen knife, and cutting off the dead victim’s finger to get to a ring.

As McCarthy breathed her last breath while lying on the prison gurney, she reportedly uttered: “God is great.”

McCarthy is the first woman executed in the U.S. since 2010 and only the 13th woman ever executed. Texas has a population of 26 million, or 8 percent of the national total, but is responsible for 40 percent of the more than 1,300 executions that have taken place in the U.S. since the Supreme Court ruled that states could reinstitute the death penalty. Since then, 32 states reinstituted capital punishment, but Texas justice leads the way, by far, in using it.