A 'lifelong criminal' is being pursued by US Marshals for allegedly killing a Pennsylvania woman and burying her in a shallow grave.

On Wednesday, the U.S. Marshals Service is searching for a "longtime offender" who is accused of murdering his ex-girlfriend and then burying her in a shallow grave in Philadelphia.

The body of Melody Rivera was discovered in Philadelphia's Fox Chase neighborhood last month, and a total of $25,000 in rewards is being offered for information leading to the arrest of Geovanni Otero, 29. Supervisory Deputy U.S. Marshal Robert Clark told Planet Chronicle Digital on Wednesday that Rivera's death was ruled a homicide by violence.

"Our task force was designed specifically to locate individuals with criminal histories, like Geovanni Otero, who has been a criminal since the age of 12," Clark stated.

"Clark advised him to surrender or risk encountering members of the Marshals task force, as he is a dangerous person who needs to be taken off the streets."

According to WPVI, the reason for Rivera's disappearance on Oct. 31 is unclear, but police believe there was a dispute between Rivera and Otero prior to the incident.

Otero, who was recently released from state prison for a firearms offense, stopped communicating with his parole officer after Rivera's death, according to records and police.

The Philadelphia Police Department declined to comment on a request from Planet Chronicle Digital on Wednesday.

Rivera's family described her as funny, loving, and kind, and stated that she leaves behind an 11-year-old daughter.

"Martha Lee Fred, a family member, stated to the station that they searched for her sister every day for hours on end. "She didn't deserve to be buried in a park. She didn't deserve that," Martha said."

Otero, also known as "Gozer," is 5 feet 10 inches tall and weighs 175 pounds, according to the U.S. Marshals Service.

"He has black hair, brown eyes, and tattoos covering the top of both hands and a tattoo of a dagger behind his left ear. His last known address was in the 5800 block of N. Park Avenue in Philadelphia."

The Marshals Service stated that the Violent Crimes Fugitive Task Force is the lead investigative agency responsible for capturing Otero for the murder and state parole warrants.