Washington ? District of Columbia police are seeking an arrest warrant against a Salvadoran immigrant in connection with the eight-year-old slaying of federal intern Chandra Levy, one of the most famous unsolved homicide cases in Washington history, according to law enforcement sources.

Levy’s parents said D.C. police officials told them late Friday that they planned to make an arrest within “the next couple of days.”

In an interview Saturday, Susan Levy, Chandra’s mother, said she was told by D.C. Police Chief Cathy L. Lanier and Lt. Michael Farish, a supervisor of the department’s cold-case squad, that investigators had made a breakthrough.

The case has been bedeviled by furious media attention and costly police mistakes. Levy, who was a 24-year-old intern for the federal Bureau of Prisons, was having an affair with Gary Condit, a married congressman from California, when she vanished. Police initially focused on Condit.

He was not charged and lost a re-election bid in 2002. He has long maintained that he had nothing to do with Levy’s disappearance.

Sources with knowledge of the case and speaking under the condition of anonymity said police are moving toward arresting Ingmar Guandique, 27.

About the time of Levy’s disappearance in May 2001, Guandique, a day laborer, attacked two women at knifepoint in Rock Creek Park, where Levy’s remains were found a year later. Guandique is serving a 10-year sentence at the U.S. Penitentiary-Victorville in Adelanto, Calif., for the two attacks.

Levy said Lanier told her that “in all her 19 years of police work, this is really big — ‘We really came down with a break.’ They’re very proud.”

Levy said she and her husband, Robert, were still processing the information.

“It’s a bittersweet relief,” she said. “Not that we’ll ever get our daughter back, but we need the truth.”

Local television stations in Washington and California began reporting late Friday that an arrest was possible.

The Levys said Lanier did not tell them who the suspect is. Lanier issued a statement Saturday declining to comment.

The police probe into Levy’s killing ramped up in recent months after The Washington Post in July published a 13-part serial narrative investigation into the case that pointed to Guandique as the most likely suspect. He has denied any involvement in Levy’s death.