A US jury has decided against the death penalty for Lee Boyd Malvo, convicted of one of the murders in last year's Washington sniper killings.
The defence argued Malvo was brainwashed by his older accomplice
The eight women and four men debated for more than eight hours before recommending the 18-year-old should face life in jail without parole.
Malvo was convicted of killing Linda Franklin, 47, outside a store in Falls Church, Virginia, on 14 October, 2002.
Last month, a jury recommended his older companion should face execution.
Ten people died during the three-week killing spree in the Washington area.
Malvo was found guilty last week of capital murder and terrorism, after he and John Allen Muhammad, 42, demanded $10m from the US Government to stop the killings.
Under Virginia state law, the jury had the power to recommend the death penalty for Malvo.
The jury instead opted for the only other alternative open to it - life in prison without parole.
Malvo's defence lawyers had argued that in deciding the sentence his youth should be taken into account. He was just 17 at the time of the shootings.
The judge is expected to formally pass the sentence next year.
Both Malvo and Muhammad could still face trial over other shootings in Virginia and other states. If convicted, Malvo could yet face the death penalty.
Attorney General John Ashcroft had cited Virginia's ability to impose "the ultimate sanction" for the decision to try the pair in Virginia.
'Under Muhammad's spell'
Malvo's defence team argued the teenager had been under the spell of Muhammad, whom he looked up to as a father figure.
The defence also argued that Malvo was temporarily insane because Muhammad's brainwashing had made him unable to distinguish between right and wrong.
Malvo and Muhammad shot their victims from inside the boot of their car
But the prosecution argued that Malvo was as responsible as Muhammad, calling them "peas in a pod".
Malvo had initially claimed he was the gunman in all the shootings, but later said Muhammad shot all but the last victim.
In his confession to police, Malvo gloated about the killings, saying: "I intended to kill them all."
The pair were eventually caught while asleep in their car, which had been modified to allow them to shoot their victims while hidden inside the boot.