JACKSON, Miss. (AP) — A black Mississippi man who has been tried six times for murder says his latest conviction and death sentence should be thrown out for a familiar reason — the prosecutor’s practice of keeping African-Americans off the jury.

Curtis Flowers has been jailed in Mississippi for 22 years, even as prosecutors couldn’t get a murder conviction against him to stick through his first five trials.

Three convictions were tossed out, and two other juries couldn’t reach unanimous verdicts.

The justices on Wednesday will examine whether District Attorney Doug Evans’ history of excluding black jurors should figure in determining if Evans again crossed a line when he struck five African-Americans from the jury that most recently convicted Flowers of killing four people.

In overturning Flowers’ third conviction, the Mississippi Supreme Court called Evans’ exclusion of 15 black prospective jurors “as strong a prima facie case of racial discrimination as we have seen” in challenges to jury composition. This time around, though, the state’s high court has twice rejected Flowers’ claims, even after being ordered by the U.S. Supreme Court to take another look.

Wednesday’s arguments at the high court are the latest stop on a twisting path that began July 16, 1996. That’s when four people were found dead inside Tardy Furniture in downtown Winona. Shot in the head were 59-year-old owner Bertha Tardy and three employees — 45-year-old Carmen Rigby, 42-year-old Robert Golden and 16-year-old Derrick “Bobo” Stewart.

It was months before officials arrested and charged Curtis Flowers for the murder. Prosecutors say Flowers was a disgruntled former employee who sought revenge against Tardy because she fired him and withheld most of his pay to cover the cost of merchandise he damaged. Nearly $300 was found missing after the killings.

Defense lawyers, though, say witness statements and physical evidence against Flowers are too weak to convict him. A jailhouse informant who claimed Flowers confessed to him recanted in recorded telephone conversations with American Public Media’s “In the Dark” podcast. There’s a separate appeal pending in state court questioning Flowers’ actual guilt, citing in part evidence that reporters for “In the Dark” detailed.