The number of executions in the US in 2015 is the lowest in nearly 25 years, new figures reveal.
A total of 28 people have been executed so far this year, Death Penalty Information Center (DPIC) figures show.
Death sentences dropped 33% from last year's historic low, with only 49 people sentenced to death. For the first time since 1995, the number of people on death row fell below 3,000.
Only six states carried out executions in 2015 - 13 of those were in Texas.
Six capital punishments were carried out in Missouri - which in September was reported to be executing its death row inmates faster than any other state in the country - and five in Georgia.
Texas, Missouri and Georgia accounted for 86% of all executions, says the DPIC, a group that opposes the death penalty and tracks executions.
Death sentences have been steadily declining in the US over the past 15 years, the DPIC says.
Its executive director, Robert Dunham, said that the use of the death penalty was becoming "increasingly rare and increasingly isolated" throughout the US.
"These are not just annual blips in statistics, but reflect a broad change in attitudes about capital punishment across the country," Mr Dunham said.
The DPIC figures revealed:
- The county of Riverside in California imposed 16% of all death sentences in the US
- More than a quarter of death sentences were imposed by Florida and Alabama after non-unanimous jury recommendations of death - a practice barred in all except three states
- At least 70 death row prisoners with execution dates in 2015 received stays, reprieves or commutations, 2.5 times the number who were executed
- Two-thirds of the 28 people executed in 2015 exhibited symptoms of severe mental illness
Six death row prisoners were exonerated of all charges this year, one each in Alabama, Arizona, Florida, Georgia, Mississippi and Texas. Since 1973, a total of 156 inmates have been exonerated and freed from death row.
Critics say there are inherent problems in how the death penalty is meted out in the US. Each state has individual laws about what types of murder are eligible for the death penalty - and within those states, similar crimes might be treated differently depending on the prosecutor.
Capital punishment in the US
- The death penalty is a legal punishment in 31 states
- Nineteen have abolished the death penalty, the most recent was Nebraska in May 2015
- Since 1976 Texas has carried out the most executions (531), followed by Oklahoma (112) and Virginia (111)
- In July 2015, there were 2,984 inmates on death row throughout the US, including more than 50 women
- California has the most prisoners on death row (746 as of July 2015)