The Los Angeles Police detective who headed the investigation into the murder of Notorious B.I.G. testified Thursday that Death Row Records honcho Marion "Suge" Knight — and not a rogue cop — was the No. 1 suspect in the rapper's 1997 slaying.

Retired Robbery-Homicide Det. Fred Miller told a six-man, three-woman federal jury that detectives combed through more than 400 clues after the slaying of the rapper, born Christopher Wallace, but couldn't close the case.

"At one time I thought we had enough evidence" to arrest Knight, said Miller, who was called as a witness for the Wallace family. "We were just not quite there to make a filing."

Knight could not be reached for comment, but has repeatedly denied any involvement in Wallace's murder.

Miller was the latest in a string of witnesses who failed to support — and in some cases directly contradicted — the Wallace family's theory that renegade LAPD Officer David Mack, now serving 14 years in prison for bank robbery, orchestrated the rapper's killing as part of violent feud between Knight's Los Angeles rap label and the company producing Wallace's music, New York-based Bad Boy Entertainment.

U.S. District Court Judge Florence-Marie Cooper ruled earlier that the family members must demonstrate that Mack, acting in his police capacity, arranged the killing before they can press federal civil rights claims against the city of Los Angeles.

The family, contending the city was involved in the murder then covered it up, is seeking unspecified monetary damages.

Wallace was gunned down March 9, 1997, after a music industry party at the Petersen Automotive Museum on Wilshire Boulevard.

Theories of the case have fueled a cottage industry of books, documentaries and magazine articles exploring the slayings of Wallace and Tupac Shakur, a Death Row artist and the other leading rap musician of his generation.

Both men were gunned down in car-to-car shootings, Shakur in Las Vegas the year before Wallace.

One of the key supporters of the theory embraced by the Wallace family is Miller's former LAPD partner, Russell Poole. Poole contends Mack enlisted college friend Amir Muhammad to kill the rap artist.

Poole asserts his investigation into Wallace's death was cut short because then-police Chief Bernard C. Parks feared it would lead to unwanted revelations about the Rampart police corruption scandal.

Rafael Perez, the central figure in the Rampart scandal, was once Mack's LAPD partner.

Earlier in the day, family attorneys tried to link Parks to their conspiracy theory by trying to get a police detective to describe a photograph of Mack, Perez and Parks' daughter, who worked as a civilian police employee around the same time as the two officers.

Rumors of the photo have circulated in LAPD circles for years, but its existence has never been confirmed.

LAPD Det. Wayne Caffey said he had seen a photo of Perez and was told by others that a woman in the picture was Parks' daughter.

But Wallace family lawyer Perry Sanders did not produce the photograph in court, nor did he explain how it might illuminate Wallace's murder.

Reached by phone after the court hearing, Parks, now a city councilman, said multiple investigations had failed to verify the existence of a photo.

He also said there was "no shred of evidence" of any conspiracy to suppress the investigation into the Wallace shooting.