Police are searching for the boyfriend of the 35-year-old woman who was killed Saturday along with her 12-year-old son, and then burned in a fire in their Wissinoming apartment.
Carlos Rivera, described as a 25-year-old Hispanic male, is considered a "strong person of interest."
Police are offering a $20,000 reward for information that leads to his arrest.
Deveney's body was found inside a closet, and under a mattress, police said. Police said she had been choked and beaten to death while her son suffered stab wounds to his chest and neck.
Police Capt. James Clark said Rivera, who is known to have had a long-time abusive relationship with Deveney, was preventing people from entering the apartment complex when the fire began.
"He stated he would put it out," Clark said, "But he never did."
Apparently the woman and her son had just moved into the apartment with Rivera a few days prior.
Clark said an active arrest warrant is out for Rivera for allegedly robbing Deveney a few months ago.
One theory is as Rivera was physically assaulting the mother her son tried to come to her aid, and was violently stabbed by Rivera, Clark said.
Rivera is described as 6 feet tall and 170 pounds. Police said he frequents the area of D and Clearfield Streets in Kensington.
Anyone with any information is encouraged to contact the Homicide Unit at 215-686-3334 or 215-686-3335.
Follow Tommy Rowan on Twitter: @tommyrowan
Follow Metro Philadelphia on Twitter: @metrophilly
Follow Metro Philadelphia on Facebook: Metro Philadelphia