The last survey by the Pew Research Center on the death penalty was in 2013.
The numbers show 55% of U.S. adults said they favor the death penalty for people convicted of murder.
A significant minority (37%) oppose the practice.
While a majority of U.S. adults still support the death penalty, public opinion in favor of capital punishment has seen a modest decline since November 2011, the last time Pew Research asked the question. In 2011, fully six-in-ten U.S. adults (62%) favored the death penalty for murder convictions, and 31% opposed it.
The death penalty debate recently increased after problems with a new drug combination left an Oklahoma inmate clenching his teeth on the gurney.
The execution has fueled more debate about the ability of states to administer lethal injections that meet the U.S. Constitution's requirement they be neither cruel nor unusual punishment.
That is the question defense attorneys and death penalty opponents are now asking.
Pew researchers say support for capital punishment has ebbed and flowed, but has been gradually ticking downward for the past two decades.
In 1996, 78% of people polled supported the death penalty and 18% opposed it.
Political party makes a big difference.
Seven-in-ten Republicans, or 71%, support for the death penalty, while 45% of Democrats agree.