Richard Kenneth Djerf, 55, is scheduled to be executed Friday in Arizona for the 1993 murders of four members of the Luna family in Phoenix.

Djerf pleaded guilty to killing Albert Luna Sr., Patricia Luna, their 18-year-old daughter Rochelle, and 5-year-old son Damien as an act of revenge over a past theft, committing the attacks with extreme violence.

He has been in prison for over 29 years and chose not to seek clemency.

If carried out, this will be Arizona’s second execution of the year and the 39th in the U.S. nationwide, the AP has reported.

Arizona’s lethal injection procedures have faced scrutiny in the past, with prior pauses due to drug shortages and botched executions; the state has 108 prisoners currently on death row.