The assailant in a hooded sweat shirt broke into the home of Hoa Pham and his wife and in what could have been a burglary gone bad.
The couple had gone to bed early and, perhaps, the thug thought no one was home.
The 60-year old Pham was beaten, tied up, stabbed, and finally killed while trying to fight off the attacker who had also beaten and repeatedly sexually assaulted his 58-year-old wife.
Police in Upper Darby have spoken to Philadelphia police about a series of attacks there, including one last month on Clinton Street in Center City.
A man followed a couple into the apartment bound them, terrorized them, and raped the woman.
Upper Darby police say while there are similarities there are more dissimiliarities.
They are also looking at cases in Ridley and New Castle, Delaware.
Meanwhile, a viewing is set for Friday night at Saint Alice's Church where Pham and his wife were active members.
A funeral mass is set for Saturday at ten.
Police have collected DNA evidence from the scene. It is being analyzed, but still there are no suspects.
Pham's wife is still hospitalized and police have not been able to interview her.
There is a $5,000 reward being offered in this case.
Anyone with information is asked to call Darby Detectives at (610) 734-7677