When Muhammad is questioned by a Fairfax County policeman in the parking lot, the policeman is shown wearing a star-shaped badge on his uniform. The Fairfax County Police Department uses shield-shaped badge, an image of which is visible on the policeman's car door.
When the MCPD respond to the phone booth, patrol officers are seen apprehending the callers, when it was actually a SWAT unit that did.
Claudine Lee Parker, the woman killed in the store robbery early in the film, was black, but in the movie, she is shown as being white.
At the end scene where the two are arrested at a rest area in Hagerstown, Maryland there is an interstate sign for I-70 South. Interstate 70 does not run south rather runs east west from Utah to Baltimore.
In one scene where the snipers are stopped by a Fairfax County policeman, there is a Home Outfitters store prominently visible in the background. Home Outfitters does not have any stores in Fairfax County, Virginia, or the United States, as it is a Canadian company.
There are tall pine trees visible in many shots that are not native to the Washington, D.C. metropolitan area.
During the middle school shooting scene aftermath, there are many Montgomery County police cars visible at the school alongside Prince George's County ones. The school was in Prince George's County, so it would make more sense to have their police there than Montgomery County's.
Early in the film, when Chief Moose drives around Montgomery County, he drives past "Lucky Loonies", which is a Canadian store in Port Coquitlam, British Columbia.