Michael Ciaccia, 28, has been charged with murder.
Police sources say Ciaccia and his brother crafted a plan to collect the victim's retirement money to fund their drug habit.
Ciaccia's brother, Andrew, and his girlfriend, Vanessa Pena, are charged with helping to hide the body.
One week ago, 70-year-old Robert Derer's body was discovered in a blue bin inside a Frankford apartment where we was staying with three roommates. Now those roommates are being charged in connection to his death.
The medical examiner determined blunt force trauma was the cause of death.
Police sources say the couple, Andrew Ciaccia and Vanessa Pena, were caught on camera purchasing the blue bin that the victim was found in.
Investigators say a drug habit was at the center of this scheme. Their plan was laid out in "communications" between the brothers found by detectives.
The trio allegedly wanted to keep Derer in the home against his will and continue to cash in on his pension and social security checks.
Instead, police say Derer was murdered.
His body was discovered soon after his family reported him missing.