Investigators say 29-year-old Geovanni Otero killed his ex-girlfriend, 29-year-old Melody Rivera.
Her body was found in a shallow grave in the 900 block of Tustin Avenue in Philadelphia's Fox Chase section on November 7.
She had been bludgeoned to death.
"I'm traumatized by what happened to my daughter," said Rivera's mother, Maritza Fred Garcia.
"She's laid to rest, but closure is still not there," said Rivera's sister, Martha Fred.
RELATED: Family pleas for help to find the person of interest in missing mom's death
The two were last seen together on October 31 in the 900 block of Sanger Street.
Police say Otero had a dispute with the victim before she went missing. That began the initial police investigation and search.
"She didn't deserve this, especially by someone who supposedly loved her," Fred said.
The motive is still unclear, but authorities say Otero has an extensive criminal history dating back to the age of 12.
Records show he was recently released from state prison for a firearms offense.
Investigators say after Rivera's murder he stopped reporting to his parole officer.
"We're considering him the most wanted person in the city now," said Rob Clark of the U.S. Marshals. "It's not a matter of if we're going to catch him, it's a matter of when."
"I want him caught. He will be caught. He will be caught. I have faith he will be caught," said Fred.
The Philadelphia Police Department asks anyone with information on the whereabouts of Geovanni Otero to contact Homicide Detectives at 215-686-3334 or to submit a tip via their anonymous tipline at 215-686-TIPS. You can also call 1-866-865-TIPS(8477).
He is being considered armed and dangerous, police say.