The court has also set an execution date of Aug. 7 for Kenneth Baumruk, who at 70 is Missouri’s oldest death row inmate, though anticipated appeals could push that date back. Baumruk was convicted for killing his wife and wounding four others during a 1992 shooting rampage at the St. Louis County Courthouse.

The governor doesn’t have a say in setting execution dates, but he can spare the lives of inmates through clemency. Gov. Jay Nixon, the state’s longtime attorney general, is a staunch supporter of capital punishment.

In Missouri, 28 inmates have been on death row for more than a decade. Five have been there since the 1980s.

Dieter believes any increase in executions will be relatively short-lived because fewer convicted killers are receiving a death sentence.

“I think juries are being more skeptical,” said Dieter, whose organization is critical of the death penalty and its application. “They’re sentencing people to life without parole instead. Prosecutors know it’s going to take 10 to 15 years of appeals, and then it may be overturned. So they’re more willing to accept plea bargains.”

Dieter said that in the 1990s, about 300 people were sentenced to death each year. Nationally last year, 115 received the death sentence.

Missouri averaged about 10 death sentences per year through the 1990s, Dieter said. According to the most recent Bureau of Justice statistics, one person was sentenced to death in Missouri courts in 2007, four in 2006, two in 2005.