Robert Offerman and Alexandria Manning Murders

The Robert Offerman and Alexandria Manning Murders were a double homicide discovered on December 30, 1979, at a condominium in Goleta. Clues inside and around the home—forced entry, nylon twine, and the intruder’s apparent movement through nearby properties—made the crime part of a larger pattern investigators struggled to explain. The Santa Barbara County Sheriff’s Department proposed that the murders might be connected to other attacks, but the theory met skepticism elsewhere, and the case remained unresolved for years.

Discovery and the scene

On the morning of December 30, friends arrived at 767 Avenida Pequena for a scheduled tennis game with osteopathic surgeon Dr. Robert Offerman and his new girlfriend, Debra Alexandria Manning. They found a sliding glass door open and received no answer when they called inside. One friend looked down the hallway toward the bedroom, saw a woman on the bed, and initially thought it best to leave without disturbing the couple. After stopping to reconsider, he returned to look more closely. When deputies arrived, Manning’s friend was outside, crying, and told them that two people were dead inside.

Manning was on one side of the waterbed, her wrists bound behind her with white nylon twine. Offerman was at the foot of the bed, holding a piece of the same material. Pry marks suggested that the intruder had forced entry with a screwdriver, probably during the night while the couple slept. Two of Manning’s rings were found hidden between the mattress and bed frame. Investigators considered whether the attacker had presented the intrusion as a robbery, although the concealed rings complicated that explanation.

Investigators believed the intruder may have thrown the twine to Manning and ordered her to bind Offerman. Her work was not tight, and they thought Offerman might have freed himself and tried to fight back. Neighbors reported gunfire at about three in the morning: an initial burst, a pause, and then another shot. The couple were killed. These details offered a possible sequence of events, but they did not identify the intruder or establish precisely what happened inside the bedroom.

Signs of movement beyond the condominium

The evidence extended beyond the bedroom. Investigators traced a star-shaped pattern left by Adidas running shoes as the intruder moved around Offerman’s condominium. A flowerbed at the vacant unit next door had been trampled. Signs that someone had been staying there were found inside, especially in the bathroom, where another length of nylon twine had been left behind. The neighboring unit thus appeared not merely as a point beside the crime scene, but as part of the intruder’s activity in the area.

Reports also described break-ins and disturbances in the neighborhood during the hours before the murders. At about 10:15 p.m., residents returning to a home on Windsor Court, roughly half a mile away, saw a man run through their living room and escape over a rear fence. They could describe him only as a white man wearing a dark fisherman’s hat and jacket. In the days after the killings, investigators found further pieces of nylon twine at different locations, including a dirt trail beside San Jose Creek and a lawn on Queen Ann Lane. The timing of the Queen Ann Lane material was uncertain, but the street was close to the home of a couple who had escaped an earlier attack.

Taken together, the clues suggested that the killer had been moving through the neighborhood before and after entering the condominium, rather than appearing only at the scene of the murders. The reports’ recurring details—twine, pry marks, and running-shoe impressions—offered points for comparison with other crimes, but no single clue by itself resolved the case.

A proposed connection and an unresolved case

The Santa Barbara County Sheriff’s Department was the first to raise the possibility that the murders belonged to a broader series. Its investigators had two double homicides and a knife attack in which the couple escaped. Officials in Ventura and Orange Counties played down the proposed connection. Ventura investigators, whose own double-homicide case had recently faltered at a highly publicized preliminary hearing, thought Santa Barbara had moved too quickly; an Orange County investigator also expressed skepticism. In August 1981, newspaper coverage questioned whether the Harrington case and other recent Southern California double homicides might be related. The discussion put the possibility before the public, but it did not amount to an accepted conclusion among the agencies involved.

For years, the case yielded no decisive tip. The files were reviewed periodically, but the necessary information did not emerge. Roger Harrington, whose son Keith and daughter-in-law Patty had also been murdered, hired a private investigator, offered a substantial reward, and arranged for friends and coworkers to be interviewed again. He even consulted a clairvoyant in desperation. None of these efforts supplied an answer. His attention returned repeatedly to the fragmented details of the murders, which remained unresolved in his mind as well as in the investigative files.

A later forensic development brought the investigation closer to an answer. Three glass tubes stored in manila envelopes, untouched for fifteen years, were opened and tested in October and November 1996. By December, investigators had results and were preparing to contact families. Roger Harrington had died on March 8, 1995, and never received the news. The later account also explains a detail he had interpreted as remorse: the bedspread covering the Harringtons’ heads was not evidence that the killer felt sorry for what he had done. The explanation given was practical—the killer did not want blood on himself after a previous, messy killing. The eventual testing and reinterpretation sharpened the meaning of the earlier cases, but came too late for a family member who had spent years waiting to learn what had happened.