Charges Will Not Be Filed in Kanan Case : Crime: An informant identified the wealthy landowner’s nephew as the killer, police said. But investigators couldn’t corroborate some details.

Prosecutors have decided not to file charges against a man suspected of the highly publicized slaying six years ago of his aunt, a wealthy landowner and descendant of a pioneer Agoura family. However, Los Angeles police continue to identify him as the prime suspect.

After a lengthy review by the Los Angeles County district attorney’s office, prosecutors decided there was insufficient evidence to charge Michael Kanan, 34, with the murder of Judy Kanan, said Sandi Gibbons, spokeswoman for the prosecutors’ office.

Michael Kanan, through his attorney, has in the past denied any part in the killing.

Judy Kanan, 68, a descendant of the family that settled Agoura in the 1860s, was shot four times by a masked gunman in a raincoat who approached her as she arrived at a Woodland Hills stable on July 29, 1985, to feed horses she kept there.

The killer escaped and no arrests were made. Early last year, an informant who said he was troubled by feelings of guilt contacted police and identified Michael Kanan, son of the victim’s brother, as the gunman.

According to court records, the informant said the slaying was motivated by long-simmering family tensions brought to a head by a dispute over a $2,600 loan from Judy Kanan to Michael Kanan’s father, George Richard Kanan.

Detectives felt no need to arrest Michael Kanan because he was already in jail for violating probation terms on an unrelated burglary conviction. He is now serving a two-year prison term for the probation violation.

After corroborating parts of the informant’s story of how the murder took place, detectives seeking a murder charge submitted the case to the district attorney late last year.

Gibbons declined to reveal why the case was rejected, saying the investigation is continuing.

The investigators on the case did not dispute the district attorney’s decision not to file charges.

“It was a close call,” Lt. William Gaida said, and Michael Kanan “remains the primary suspect. We need to get additional information or evidence. We consider the informant to be reliable and we are convinced we are looking in the right direction.”

According to court records filed during the investigation, Michael Kanan had once asked the informant to help him kill Judy Kanan, suggesting a plan that was similar to the way the actual killing occurred.

The informant, according to the court records, said the slaying was later carried out without his involvement, and afterward Michael Kanan told him, “It’s a real trip to see something you are responsible for. . . . The bitch got what she deserved.”

The informant also told investigators of a storage locker Michael Kanan used where police then seized a raincoat and gloves officers believe were worn during the killing.

However, police conceded that the informant’s credibility could be questioned by a jury if the case were brought to trial now because some of the details of the crime he gave police could not be corroborated by investigators.

The gun used in the slaying has never been found. A key part of the informant’s story was that Michael Kanan stole the gun from a car parked by a jogger in the Sepulveda Dam Recreation Area, said Detective Phil Quartararo.

Quartararo reviewed reports of hundreds of crimes in that area in the months before the killing without discovering one involving such a theft, he said.

Quartararo, who has been assigned to the killing from the beginning, said he has no plans to drop the case, but the investigation has gone “as far as we may be able to go unless somebody else comes forward.”