NASHVILLE (AP) — Tennessee on Monday set two new execution dates, days after putting to death its seventh inmate in the past year and a half.

The Tennessee Supreme Court ordered an Oct. 8 execution date for Byron Black and a Dec. 3 execution date for Pervis Payne.

Black was convicted by a Nashville court of murdering his girlfriend Angela Clay and her daughters Latoya, 9, and Lakesha, 6, at their home in 1988. Prosecutors said he shot the three during a jealous rage. Black was on work release at the time for shooting and wounding Clay's estranged husband.

Payne was sentenced to death in Memphis for the 1987 fatal stabbing of Charisse Christopher and her daughter, Lacie Jo, in what prosecutors described as a "drug-induced frenzy." Christopher's son, Nicholas, who was 3 at the time, was stabbed but survived. Payne claimed at trial that he saw someone else leave the apartment and he got blood on himself when he touched the victims after they had been stabbed.

Attorneys for the inmates have argued that both men are intellectually disabled and mentally ill. The court has ordered a competency hearing for Black to determine whether he is competent to be executed.

Attorney Kelley Henry, a supervisory assistant with the federal public defender's office in Nashville, said of Black in an emailed statement: "In addition to the severe mental defects which make him incompetent to be executed, he suffers from numerous medical ailments."

Henry's statement said Payne is "intellectually disabled," adding "he was convicted because he was unable to assist his attorneys in making his defense and made a poor witness who was no match for the experienced prosecutor."

Two other executions are already scheduled for 2020, so if all go forward as planned, Tennessee will execute five inmate this year, something it hasn't done since 1948, according to execution records from the Tennessee Department of Correction.

At least two things have made executions rare in Tennessee in the past. Stringent legal protections for death penalty cases have meant appeals can drag on for years, even decades. But even after the appeals are exhausted, challenges to lethal injection have added more delays.

A U.S. Supreme Court 2015 decision made those lethal injection challenges harder to win by requiring inmates who object to one method of execution to show there is a readily available alternative that is more humane. Tennessee inmates lost a major challenge to the state's three-drug lethal injection method in July 2018 when a court ruled they had not shown their preferred one-drug method was available.

The state began its most recent string of executions the following month.

Expert witnesses testifying in 2018 on behalf of the inmates have said state's the mix of three drugs would cause sensations of drowning, suffocation and chemical burning while rendering the inmates unable to move or call out. Five of the seven inmates executed since then have chosen to die in the state's electric chair rather than by lethal injection, with several indicating they thought electrocution would be quicker and less painful.

The electric chair is an option in Tennessee for inmates whose crimes were committed before 1999, when the state first adopted the use of lethal injection. The most recent inmate to die that way was Nicholas Sutton, who was executed on Thursday.