Defense lawyers want the alleged confession tossed but prosecutors say Malvo freely admitted to shooting FBI analyst Linda Franklin at a Home Depot in Falls Church in October.
Franklin was one of the victims in a string of sniper attacks in Virginia, Maryland and D.C. Malvo and fellow suspect John Allen Muhammad have been linked to 20 shootings, including 13 deaths across the country.
"It's Malvo's biggest day in court, by far," says CBSNews.com Legal Analyst Andrew Cohen.
Malvo's attorneys say their client was tricked into confessing, adding he shouldn't have been questioned without representation. The prosecution wants Malvo's statements admitted as evidence at his trial.
"This hearing is more critical for the defense than it is for prosecutors," says Cohen. "If Malvo's statements are allowed in as evidence, it's hard to see how he avoids a conviction and even perhaps the death penalty. But even if Malvo's statements are tossed from the case, prosecutors still have circumstantial evidence that they say links Malvo to the Franklin shooting."
The defense says that Malvo had an attorney when police questioned him last Nov. 7 so that anything he said should not be used against him at trial. Prosecutors say that Malvo might have had a Maryland attorney but he didn't have one in Virginia and, even if he did, he waived his right to remain silent so his statements can and should be introduced at trial.
Prosecutors also say that Malvo laughed and joked about his role in the death of Franklin last October.
"If this is true — and right now that's a big if — it would devastate the defense at trial," says Cohen. That's why Malvo's attorneys have focused so intently on trying to convince the judge that Malvo should never have been questioned at all once he was transferred to Virginia last fall.
"The defense cannot win this case at this hearing — there still appears to be physical evidence that prosecutors say links Malvo to the crime — but the defense might lose this case if they lose this hearing," Cohen says. A Malvo confession, or even simply incriminating statements by the young man, would almost surely convince jurors that he was involved in Franklin's death.
"We ought to hear a lot of factual nuggets that will offer context not just into what Malvo may or may not have said but also into how he was treated by law enforcement officials at a time when he was being transferred from federal to state jurisdiction and from Maryland to Virginia control," says Cohen.
The defense argues that police and prosecutors pulled a fast one on Malvo: That the federal charges against him in Maryland were dismissed without his attorneys knowing about it so he could be transferred to Virginia without giving those attorneys a chance to remind Malvo that he still had a right to remain silent. It's a claim that ought to make for some hot collars in court, predicts Cohen.