Terry L. Nichols was spared the death penalty on Friday when jurors who convicted him of 161 state murder counts in the Oklahoma City bombing deadlocked over his sentence, six years after a federal jury reached a similar impasse.
The hung jury denies prosecutors the death sentence they first demanded nearly a decade ago.
Jurors announced they could not reach a verdict after deliberating for about 19½ hours over three days. Mr. Nichols will be sentenced by Judge Steven Taylor, who is required by law to sentence him to life in prison.
Judge Taylor asked the jury foreman, Peter Mills, if more deliberations could bring about a decision. Mr. Mills said that would not help.
“Three days you have worked on this,” Judge Taylor told the jury. “And sometimes this is how cases end. The law anticipates that juries may not reach unanimous conclusions.
The deadlock was a blow to state prosecutors and victims’ family members who said that death was the appropriate punishment for the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City.
The jury, which convicted Mr. Nichols on May 26, began deliberating in the trial’s sentencing phase on Wednesday, after a week of emotional testimony. Mr. Nichols, 49, faced sentences of life in prison or death by injection.
Judge Taylor set the sentencing for Aug. 9.
The bombing on April 19, 1995, killed 168 people and wounded 500. Timothy J. McVeigh, Mr. Nichols’s former Army buddy and the mastermind of the bombing, was convicted of federal charges and executed in 2001.
Mr. Nichols was spared the death chamber after a federal trial in the late 1990’s in which he was acquitted of murder but convicted of conspiracy and involuntary manslaughter in the deaths of eight government agents. Oklahoma prosecutors then brought him to trial for the deaths of the other victims, including one fetus, with hopes of winning a death sentence.
Prosecutors said Mr. Nichols helped build the two-ton bomb, made from farm fertilizer and fuel oil, that was packed into a Ryder rental truck and detonated outside the federal building.
During closing arguments in the sentencing phase, a prosecutor, Suzanne Lister, called the bombing “one of the darkest, ugliest days in American history.”