Two remain hospitalized with non-life-threatening injuries, police say.
UMPD’s Criminal Investigations Unit is investigating this incident, according to the notice.
The two suspects were last seen armed with a handgun and running behind the store.
The Metro Transit Police Department will be conducting the robbery investigation.
It's the second reported indecent exposure on the trail this week.
The female initially reported the incident to the park police.
Police believe the suspects may have left in a vehicle, according to a community alert.
The Prince George’s County division of the Maryland-National Capital Park Police is investigating the incident.
Police responded to cases of theft, fraud and more this summer.