A freeze frame from a surveillance video of Nancy Dunning, lower left, and a person of interest inside
a Target store the day of Dunning's murder is photographed during the Charles Severance murder
trial at the Fairfax County Circuit Court in Fairfax, Va., Friday, Oct. 16, 2015.
 (AP Photo/Evan Vucci, Pool)

A photograph of Charles Severance, right, is shown next to an image of a man taken from surveillance
video leaving a Target store the day Nancy Dunning was murdered, during a murder trial at the Fairfax
 County Circuit Court in Fairfax, Va., Friday, Oct. 16, 2015.
(AP Photo/Evan Vucci, Pool)

A photo of Charles Severance is shown on a monitor during his murder trial at the Fairfax County
Circuit Court in Fairfax, Va., Friday, Oct. 16, 2015.
(AP Photo/Evan Vucci, Pool)

A photograph of the front door to the home of murder victim Nancy Dunning is shown during the trial of
Charles Severance at the Fairfax County Circuit Court in Fairfax, Va., Thursday, Oct. 15, 2015.
(AP Photo/Evan Vucci, Pool)

Evidence, including range viewfinder, is shown at the trial for alleged Alexandria serial killer Charles Severance
at the Fairfax County Circuit Court on Wednesday, October 14, 2015, in Washington, DC.
(Photo by Jahi Chikwendiu/The Washington Post)

Evidence, including clothes, is shown at the trial for alleged Alexandria serial killer Charles Severance at the
Fairfax County Circuit Court on Wednesday, October 14, 2015, in Washington, DC.
(Photo by Jahi Chikwendiu/The Washington Post)

Evidence, including a gun cleaning kit, is shown at the trial for alleged Alexandria serial killer Charles
Severance at the Fairfax County Circuit Court on Wednesday, October 14, 2015, in Washington, DC.
(Photo by Jahi Chikwendiu/The Washington Post)

Defense attorney Chris Leibig wheels a cart of evidence to the front of the courtroom at the trial for alleged
Alexandria serial killer Charles Severance at the Fairfax County Circuit Court on Wednesday,
October 14, 2015, in Washington, DC.
(Photo by Jahi Chikwendiu/The Washington Post)

Daniel Petrillo leaves the witness stand after testifying that he saw Charles Severance walking near Ron Kirby's
home on the day Kirby was killed, at the trial for alleged Alexandria serial killer Charles Severance at the
Fairfax County Circuit Court on Wednesday, October 14, 2015, in Washington, DC. 
(Photo by Jahi Chikwendiu/The Washington Post)

Alexandria Chief of Police Earl Cook testifies during the Charles Severance trial in Fairfax
County Circuit Court on Tuesday October 13, 2015 in Fairfax, VA.
(Photo by Matt McClain/ The Washington Post)

A photo of shell casings that were obtained during a search are displayed during the Charles Severance
trial in Fairfax County Circuit Court on Tuesday October 13, 2015 in Fairfax, VA.
 (Photo by Matt McClain/ The Washington Post)

A photo of ammunition that was obtained during a search is displayed during the Charles Severance
trial in Fairfax County Circuit Court on Tuesday October 13, 2015 in Fairfax, VA.
(Photo by Matt McClain/ The Washington Post)