Another man, described only as a white male, is being sought by state police. That man, also a suspect in two of the robberies, jumped out of Ernst's vehicle around Cool Hollow Road during the chase.
Police are asking anyone who saw Ernst Friday with another subject to call authorities at 301-739-2101with that other man's identity, Turano said.
State police first learned of an armed robbery at the Maugans Avenue Texaco at 18404 Maugans Ave. at 12:50 a.m., Turano said.
While that incident was being investigated, a call came from the Nibble Quik at Lappans Road and Sharpsburg Park that another armed robbery had occurred there at 3:20 a.m., Turano said.
"The trooper who was responding to the Nibble Quik spotted the suspect vehicle from the Texaco robbery, turned and pursued,'' Turano said.
No one was injured in either of the Saturday robberies, Turano said. Cpl. Denton Lowry and Trooper First Class Michael Kretzer are conducting the investigations.
A third armed robbery that occurred at the Hong Kong Restaurant, at 1075 Virginia Ave., shortly after 10 p.m. Friday is being investigated by Hagerstown City Police, Turano said.
While not ruling out that the three robberies may be related, no charges have been filed in the Hong Kong robbery, city police said.
In that incident, a man entered and displayed a knife, police said. Investigator Carroll Braun is heading up that investigation.