The Maryland trial in Montgomery County Circuit Court included Malvo's chilling insider account of his trip across the country with accomplice and mentor John Allen Muhammad.
In a brief statement in court Wednesday, Malvo apologized for his role in the killings.
"I'm truly sorry, grieved and ashamed for what I've done," said Malvo, his voice breaking.
Malvo, 21, pleaded guilty in October to the murders in Montgomery County, where the series of 13 shootings began and ended in October 2002.
However, it's unlikely that Malvo will ever serve time in a Maryland prison. He has already been sentenced to life in prison in Virginia for sniper shootings there and was sent to Maryland last year for a new trial on the condition he be returned after his case ended. That could happen within the next several days, said Darren Popkin, Montgomery County's chief deputy sheriff
Malvo testified in May against Muhammad, who was convicted of the same six Maryland murders and sentenced to life in prison. Muhammad was previously sentenced to death in Virginia.
Malvo detailed the genesis of the sniper shootings, their killing methods and Muhammad's grandiose plans for more carnage. He also confronted Muhammad, his one-time father figure, saying Muhammad had manipulated him, turning the then 17-year-old into a "monster."
Along with the Washington-area shootings, Malvo and Muhammad are either suspects in or have been charged in shootings in Alabama, Georgia, Louisiana, and Washington state. They are also linked to unsolved murders in Florida and Texas.
Last month, Malvo told investigators in Arizona that he and Muhammad were responsible for the unsolved 2002 shooting of a man on a golf course in Tucson.
Malvo's lawyers said they hoped to craft a broader agreement that would allow him to plead guilty to some of the other outstanding cases, but it was unclear if they had made any progress on such a deal.