The next day, one person was killed and two more injured after being shot near a shopping mall in Bethesda.
In a second incident on Friday, a woman was shot and killed eight miles (13 km) away shortly afterwards.
Mr Tordil is a police officer with the Federal Protection Services, which provides security to US government buildings.
He was arrested by tactical officers "without incident" near to where Friday`s second shooting took place.
Police believe he killed his estranged wife outside the High Point High School in Maryland on Thursday as she was picking up her children.
A man who went to her aid was also shot and injured.
Mr Tordil was charged with first-degree murder for his wife`s killing and assault for the shooting of the bystander at the school.
The Federal Protective Service says that Mr Tordil was placed on administrative leave in March after a protective order was issued against him.
On Friday, gunfire erupted at the Westfield Mall in Bethesda then the second shooting happened at a supermarket in nearby Aspen Hill.
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