Mary was last seen leaving her parents house on July 15, 1974 with Roger Dale Allen in an el Camino security vehicle owned by Allen Security. At the time of her disappearance, Mary worked at a Denny's Restaurant in Fresno. The last day she worked was on July 18, 1974 and she never picked up her check. For three years, she was presumed to be a runaway. During an armed robbery of a Visalia K-Mart in March 1977, Larry Green shot a bystander, and police arrested him along with Benjamin Meyer and Clarence Ray Allen. Authorities eventually linked Allen to the 1974 murder of Mary Sue Kitts, the live-in girlfriend of his son, Roger. In 1974, Clarence Ray Allen enlisted the help of his son Roger Allen, as well as other employees in Allen's security guard business, to burglarize Fran's Market. On June 29, 1974 the night of the burglary, Roger Allen invited the owners 19-year-old son, Bryon Schletewitz, to an evening swimming party at Allen's house. There, Bryon's keys to Fran's Market were taken from his pants pocket while he was swimming. Later in the evening, while Bryon was on a date arranged by Allen with Mary Sue Kitts, Allen and accomplices used Bryon's keys to burglarize his parents' market. They removed a safe from the market and divided the $500 in cash and over $10, 000 in money orders found inside. Mary contacted Bryon Schletewitz and confessed to him that she had helped to cash the money orders stolen from Fran's Market. Bryon confronted Roger Allen with this story, and Roger admitted that the Allen family had burglarized the store. When Roger told his father of Bryon's accusation based on Mary's confession, Allen ordered her to be killed. Mary was strangled to death by Allen's accomplice, Lee Furrow. Allen had his accomplices tie stones to Mary's wrapped-up body and, while he watched for traffic, dumped her into the Friant-Kern Canal. Mary's body was never recovered. Allen was tried and convicted in 1977 of robbery, attempted robbery, and assault with a deadly weapon. His arrest also led to his second 1977 trial, for the Fran's Market burglary, conspiracy, and the murder of Mary Sue Kitts. In return for testifying for the prosecution, Furrow pleaded guilty to a reduced charge of second-degree murder. Clarence Allen was sentenced to death for arranging the execution murders of three people who testified against him. He was executed by lethal injection on January 17, 2006. The canal was searched and some human bones were recovered, but police were unable to make a positive identification of them.