A man who killed two farmworkers and a teenage boy in Riverside County was sentenced to death in February, another was sentenced in April for killing an 85-year-old man. In May, four people were sentenced to death in the county in three separate cases.
All told, courts have sentenced eight people to death in Riverside County this year, more than any other county in the United States, according to a report by the Death Penalty Information Center, a Washington, D.C.-based nonprofit group.
The county accounts for 16% of all death sentences imposed in the United States this year, the report said.
The ranking comes amid a significant nationwide drop in death sentences in recent years. Texas, for example, has imposed only two new death sentences this year, and Alabama has imposed six.
Nationally, 49 new death sentences have been handed down so far in 2015, the fewest in more than four decades, the report said.
"At the same time that the numbers of death sentences and the number of executions are dropping, we're seeing that where it is aggressively carried out is becoming progressively geographically isolated," said Robert Dunham, executive director of the Death Penalty Information Center.
Since 2012, Riverside has either tied with or been a close second to Los Angeles County, which has four times its population, in the number of death sentences imposed, according to the California attorney general's office.
Last year, each county imposed three death sentences. In 2013, Riverside had six and Los Angeles had seven. In 2012, Riverside imposed four death sentences, Los Angeles six.
No prisoner has been executed in California since 2006.
Because it's unlikely a person will actually be executed here, prosecutors who aggressively pursue death are "going for status prizes," UC Berkeley law professor Franklin Zimring said.
"If you want executions, you move to Texas. If what you want to do is frame the number of death sentences you've obtained then it's a good idea to move to Riverside. Those are pretty expensive status rewards, though," he said.
Zimring said the determining factor for a large concentration of death sentences is not homicide rates or demographics, but rather, "Who is the district attorney? And what priorities do they invest in going for death sentences?"
Riverside County Dist. Atty. Mike Hestrin said the cases are about justice.
"It's not a trivial thing to ask a jury to take someone's life," he said. "I think prosecutors understand the gravity of what they're doing and they're not only very restrained when they seek death but even in the way we make arguments to a jury."
Hestrin is the county's third district attorney since 2007. The number of death sentences in the county "is a reflection of the prosecutor in office but it is in turn a reflection of the community," he said. "If the case cries out for the death penalty, then we will seek the death penalty."
When Hestrin became Riverside's top prosecutor in January, he reviewed each of 22 pending death penalty cases and decided to continue pursuing death in 16 cases, spokesman John Hall said.
Hestrin is part of a group of district attorneys, law enforcement and victims' rights advocates who are pushing for a 2016 ballot initiative that would speed up the death penalty process in California.
The initiative would create new deadlines to accelerate appeals and require that death row inmates work and pay restitution to victims.
As of Dec. 7, there were 87 inmates from Riverside County on death row, according to the state Department of Corrections and Rehabilitation.
Of the eight defendants sentenced to death this year, five are Latino, one is black, one is white and one is listed as other, according to a database maintained by the corrections department. Countywide, 38% of residents are white, 47% are Latino and about 6% are black.
In 2014, Riverside County reported 93 homicides, fewer than Los Angeles (526), San Bernardino (110) and Alameda (102) counties, according to the California attorney general's office. Each of the eight defendants sentenced this year in Riverside is awaiting an automatic appeal before the state Supreme Court.