A jury recommended in November that Muhammad be sentenced to death for the murder of Dean Harold Meyers at a gas station near Manassas, one of 13 shootings that terrorized the region during a three-week span.
Circuit Judge LeRoy F. Millette Jr. has the option of reducing that sentence to life in prison without parole when Muhammad is formally sentenced Tuesday.
Defense motions filed Friday urge leniency, citing Muhammad's lack of a previous criminal background, the effect of an execution on Muhammad's children and the general sanctity of human life.
"We do a disservice to our children when we kill," wrote defense lawyers Jonathan Shapiro and Peter Greenspun. "Whether sanctioned by the state or not, killing is killing."
Defense lawyers also argue that life in prison is a more appropriate sentence, given that a jury recommended the lesser punishment for Muhammad's partner, Lee Boyd Malvo.
Malvo is to be formally sentenced Wednesday in Chesapeake. In Virginia, judges can accept a jury's sentence recommendation or reduce it, but cannot increase it.
Muhammad's defense also wants to limit victim-impact testimony Tuesday to the Meyers family. Prosecutor Paul Ebert said Monday he wants other families who lost loved ones during the killing spree to testify.
During the trial, the judge limited victim-impact testimony to the Meyers family.
By Matthew Barakat