The jury of eight women and four men will resume its duties this morning in a case that has presented two vastly different pictures of Malvo.
Malvo is charged with two counts of capital murder in the fatal shooting of FBI analyst Linda Franklin, 47, of Arlington, Va., in the parking lot of a Home Depot store near Falls Church, Va., on Oct. 14, 2002.
Yesterday, before going home, jurors sent Circuit Judge Jane Marum Roush three questions that shed a small ray of light on the issues with which they were grappling.
The jury, which must find that Malvo acted with "malice" to convict him of capital or first-degree murder, had questions about the meaning of the word and its relevance to the legal definition of insanity.
The jury's interpretation of insanity - essentially defined in Virginia as a person's inability to tell right from wrong - is a critical factor that will likely decide the outcome of the five-week trial and whether Malvo will be dealt a death sentence.
Some legal experts say the insanity plea might be eroded by evidence that Malvo, 18, sometimes felt doubts about the murderous mission he embarked upon with his accomplice, John Allen Muhammad.
His feelings of occasional guilt, which he confided to mental health experts, would seem to undermine the defense contention that the teen-ager did not know right from wrong while in the midst of the sniper killings.
Among them is a statement Malvo made that he felt "conflicted" about shooting a 13-year-old boy at a Bowie middle school; a letter he wrote two months before the shootings began that was described as a "cry for help"; and letters he wrote to a fellow inmate in jail that showed him perhaps more cunning than defense attorneys have led the jury to believe.
"The inconsistencies with the defense theory, which were evident during the defense's own presentation, are reasons why the jury is likely to reject the insanity defense," said Steven D. Benjamin, president-elect of the Virginia Association of Criminal Defense Lawyers.
But Benjamin said that the defense can still have hope if the jury does not find Malvo insane, adding that he believes Malvo's lawyers never really expected to win an acquittal based on insanity.
Virginia juries don't buy excuses from serial killers, Benjamin said, but by waging an insanity defense, attorneys were able to introduce all sorts of evidence that normally wouldn't come into play until sentencing.
Jurors heard about Malvo's troubled and itinerant childhood, about how he was beaten often and frequently moved among homes and schools.
They heard how he was an obedient boy who wanted to go into the Air Force and become a pilot until he met Muhammad and his life changed.
Malvo's plans were set aside as Muhammad, 42, put him on a strict diet and exercise regimen and filled his head with racist and anti-American propaganda.
The intense indoctrination, the defense argues, made it impossible for the youth to tell right from wrong and thus qualifies him as legally insane.
"The defense has never sought, I contend, an acquittal by reason of insanity. Their goal has always been saving Malvo's life."
Late yesterday, jurors sent the judge three questions that appeared to focus on issues central to the trial.
In one, jurors indicated they were confused about whether two separate instructions, which explain the different components of the two capital murder charges, were really about the same charge.
That will be clarified for them.
They also asked for clarification on an instruction relating to malice, the definition of which includes a reference to one's mind being "under the control of reason." Roush, the judge, said she will tell jurors to use ordinary meanings of the words.
The jury would have to find Malvo killed with malice in order to convict him of capital or first-degree murder.
Finally, jurors asked for a second look at the 1990 Chevrolet Caprice in which Malvo and Muhammad were arrested.
However, Roush said yesterday that she will tell jurors to rely on their recollections from the first time they saw the car last month.
While the Muhammad trial was all about whether the Army veteran pulled the trigger in any of the sniper shootings, the Malvo trial has been more about why he pulled the trigger or was involved at all.
"Those things that led up to his pulling the trigger or being in the car when the trigger was pulled are relevant," said Baltimore defense attorney Warren A. Brown. "He didn't just drop out of the sky into the seat of this car with his finger on the trigger of a rifle."
Among the strongest evidence for insanity, legal experts said, are the simple facts of Malvo's life. He had no criminal record before the shootings and did well in school despite a father who deserted him and a mother who was frequently absent. He admitted killing some cats and petty thievery, but it is nothing close to what he now stands accused of.
Strong testimony also came from Muhammad's first son, Lindbergh Williams, who told the jury of how his father brainwashed him when he was 11 and they spent a summer together.
Williams called his father a "manipulator" and said Muhammad convinced him that his mother was abusing him and that he shouldn't return home.
"If he sees weakness, he'll take advantage of your weakness," said Williams, 21. "He had embedded in my head that I didn't want to go home."
Still, experts said it doesn't have to. The more important effect of such evidence is to show that Malvo is less deserving of blame for the shootings, no matter his role.
"What we have here is an imperfect insanity defense," said Benjamin, of the Virginia lawyers group. "Under the argument that he is insane, the defense is presenting what is a stronger argument for diminished culpability."
Normally, evidence about a defendant's life and mental health doesn't get introduced until sentencing.
"Without insanity, none of this would have been heard until after a capital prosecution and after the prosecution's case for death," Benjamin said.
"You want to talk about your strongest point as soon as you can. Otherwise you're buried."
The defense's case for insanity was far from perfect.
Among the biggest holes was the admission by a defense team psychiatrist that Malvo told her he felt troubled by the shooting of a 13-year-old boy at a middle school in Bowie.
Diane Schetky, a psychiatrist from Rockport, Maine, said Malvo hadn't realized that shooting children was part of Muhammad's extortion plan.
"He indicated he was conflicted about shooting the child, which is why it wasn't a head shot," Schetky testified. "He didn't practice shooting children. He practiced shooting adults. They didn't have cutouts of children on the trees where they practiced."
While the letter might show the control that Muhammad exerted, it can also be seen as showing Malvo was aware of the control.
"I have a father who I know is going to have to kill me for a righteous society to prevail," said the letter, which was written to a niece of Muhammad's in Baton Rouge, La.
Jurors also were told of letters Malvo wrote to a fellow inmate at the Fairfax County Detention Center in the late summer and fall of this year. By that time, Malvo's psychiatrists claimed he had broken free of Muhammad's spell.
But experts say the letters could lead a jury to believe Malvo is just as manipulative and cunning as Muhammad.
Malvo writes in one letter, "I play the stupid fool. Look at how I act and speak. Everybody underestimates me. ... I love that, it gives me the edge I need to study, conquer and overcome."
Staff writer Andrea F. Siegel contributed to this article.