With those witnesses, the prosecution rested Monday. On Tuesday, lawyers for both sides and Circuit Judge Jane Marum Roush were to work out jury instructions. Roush estimated jurors would hear closing statements Tuesday afternoon, then begin deliberations.
The psychologists' testimony Monday as rebuttal witnesses contradicted defense mental health experts who had described Malvo as malleable and vulnerable to brainwashing by sniper mastermind John Allen Muhammad.
Defense attorneys say Malvo was insane at the time of the shootings because of indoctrination by Muhammad.
Psychologist Evan Nelson, who met with Malvo several times last month for a total of 15 hours, said Muhammad "had a tremendous influence on this young person, absolutely." But it wasn't brainwashing, Nelson said; instead, Malvo idolized Muhammad.
"He felt like it was a partnership," Nelson said.
Nelson also said Malvo's behavior, which included meticulous planning of the killings, "is the antithesis of someone who cannot control his impulses."
Malvo was narcissistic and needed to feel superior, Nelson said. But Nelson disputed the idea that Malvo's ability to "zone out" during a killing amounted to a mental illness.
"In my opinion, he very clearly possessed the capacity to tell the difference between right and wrong as he was committing these offenses," Nelson said.
Nelson also said Malvo's repudiation of Muhammad this past summer may have been an inadvertent form of brainwashing at the hands of Malvo's defense team, who persuaded him to reject Muhammad's teachings.
Both Nelson and psychologist Stanton Samenow described Malvo as bright. Nelson suggested that Malvo's intelligence would make it easy for him to feign mental illness.
Earlier, Samenow, who interviewed Malvo eight times last month for a total of more than 34 hours, said Malvo described himself as independent and emotionless and "nobody's fool."
"Mr. Malvo knows exactly what he is doing," Samenow said. "He knew what he was doing with me. He said to me that he is not impressionable."
Samenow said he saw no evidence of mental illness.
"He did know right from wrong" on Oct. 14, 2002, when FBI analyst Linda Franklin was shot dead, Samenow said. Malvo is charged with capital murder in her slaying and could get the death penalty if convicted.
Samenow also said Malvo showed a strong will and hot temper from an early age.
Malvo, 18, and Muhammad, 42, are accused of carrying out a series of shootings that killed 10 people over three weeks last year.
In a separate trial last month, Muhammad was convicted of another of the killings and a jury recommended a death sentence. The 42-year-old Army veteran was convicted of killing Dean Harold Meyers at a northern Virginia gas station during the rampage.
"In virtually every way, Malvo's attorneys presented a much more complete defense than we saw in the trial of John Muhammad," said CBSNews.com Legal Analyst Andrew Cohen. "They focused upon Malvo's background, on his youth, on his relationship with Muhammad and on his mental state at the time of the shootings and I think in doing so gave jurors who are inclined to be sympathetic something to hold onto."