The fire broke out around 6:35 a.m. at 1534 Foulkrod Street.
A witness told police he saw a man firing shots at the house.
The witness said the man then broke down the front door and tossed a bottle containing an ignited rag inside - a Molotov cocktail.
The man then ran off as the house erupted in flames.
The witness told police a second man came out of the house and was rolling on the ground, apparently trying to put out the fire on his clothes.
He also ran off down the street, holding his leg.
Later, police got a call from Northeast Philadelphia from a man who wanted to report his car stolen.
The 34-year-old man matched the description of the suspected gun-wielding arsonist on Foulkrod and was arrested.
Charges are pending.
Police still have not been able to track down any victim from Foulkrod Street.
Authorities were notified of an unidentified man suffering from burns at Temple University Hospital.
However, they do not believe the John Doe has any connection to the case.