In September 2003, Muhammad was sentenced to death. One month later, Malvo was sentenced to six consecutive life sentences without the possibility of parole. On November 10, 2009, Muhammad was executed by lethal injection.

On August 1, 2002, about 8:20 p.m, John Gaeta was shot in Hammond, Louisiana, by Malvo. The bullet pierced his neck and exited his back, just below the shoulder. Doctors found he had avoided damage to his spine and arteries and he was released in about an hour. On March 1, 2010, he received a letter of apology from Malvo.

On September 5, 2002, at 10:30 p.m., Paul LaRuffa, a 55-year-old pizzeria owner, was shot six times at close range while locking up his Italian restaurant in Clinton, Maryland. LaRuffa survived the shooting, and his laptop computer was found in John Allen Muhammad's car when he and Malvo were arrested.

On September 21, 2002, Claudine Parker, a liquor store clerk in Montgomery, Alabama, was shot and killed during a robbery. Her co-worker, Kellie Adams, was injured, but survived. Evidence found at the crime scene eventually tied this killing to the Beltway attacks and allowed authorities to identify Muhammad and Malvo as suspects, although this connection was not made until October 17. Mohammad and Malvo were also linked to the September 23rd killing of Hong Im Ballenger in Baton Rouge, Louisiana.

At 5:20 p.m. on October 2, 2002, a shot was fired through a window of a Michaels craft store in Aspen Hill. As no one was injured, no serious alarms were raised. About an hour later, at 6:30 p.m., James Martin, a 55-year-old program analyst at NOAA, was shot and killed in the parking lot of a Shoppers Food Warehouse grocery store, located in Glenmont.

On the morning of October 3, four people were shot within a span of approximately 2 hours in Aspen Hill, and other nearby areas in Montgomery County. Another was killed that evening in the District of Columbia, just over the border from Silver Spring.

In each shooting, the victims were killed by a single bullet fired from some distance. The pattern was not detected until after the shootings occurred on October 3.

Fear quickly spread throughout the community as news of the shootings spread. Many parents went to pick up their children at school early, not allowing them to take a school bus or walk home alone. Montgomery County Public Schools, District of Columbia Public Schools, and private schools went into a lockdown, with no recess or outdoor gym classes. Other school districts in the area also took precautionary measures, keeping students indoors.

At this point Malvo and Muhammad started covering a wider area and taking more time between shootings. On October 4, 43-year-old Caroline Seawell was wounded at 2:30 p.m. in the parking lot of a Michaels Craft Store at Spotsylvania Mall in Spotsylvania County, Virginia, just outside the city of Fredericksburg, while she was loading purchases into her minivan.

On October 7, at 8:09 a.m., Iran Brown, a 13-year-old boy, was shot — accounts vary between the lower body, stomach and chest — as he arrived at the Benjamin Tasker Middle School in Bowie, Maryland, in Prince George's County (Brown's name was concealed from the public but was later revealed). His aunt, a nurse who had just brought him to school, rushed him to a hospital emergency room. Despite serious injuries, including damage to several major organs, Brown survived from the attack and ultimately testified at Muhammad's trial. At this crime scene the authorities discovered a shell casing as well as a Tarot card (the Death card) inscribed with the phrase, "Call me God" on the front and, on three separate lines on the back, "For you mr. Police." "Code: 'Call me God'." and "Do not release to the press."