Detectives identified Robert Leroy Burkey, 25, of the first block of Lewis Drive, as the man who demanded money from a BP employee at knifepoint, at about 1:30 a.m. on Wednesday.
The employee did not report the incident to police until seven hours later.
Burkey was charged with robbery, armed robbery, theft less than $1,000 and possession of a dangerous weapon with intent to injure. He was ordered held on $75,000 bail by District Court Judge Lawrence Lanahan on Monday.
On Thursday night, shortly after Burkey was brought in and charged, another robbery attempt was reported at 11:25 p.m.
Police said a white man, wearing black clothing with a black bandanna covering his face, entered the station and displayed a knife while demanding money.
The employee immediately called 911 and the robber fled in an unknown direction.
Burkey has only been identified as the suspect in the Wednesday robbery, Ofc. Jeff Gilpin said Tuesday, explaining the detectives have not yet identified the suspect in Thursday's robbery.
"Detectives are currently investigating this incident and are considering the possibility that this incident may be related to the previous instance at the BP and the other incidents that have occurred in Harford County," Gilpin said.
This is the third robbery or attempted robbery reported at the BP station in less than a year.
Two 18-year-old men from Havre de Grace were recently arrested in a robbery involving a gun in August 2012.
Police seem to be keeping a closer eye on the station, as one Havre de Grace police car was parked on the other side of a fence behind the station Monday night.