Hensley's family last heard from her in February 1973. They didn't realize she was missing until March 1974, and she wasn't officially reported missing for over 35 years.
Her boyfriend, William Felix Vail Sr., who is addressed by his middle name, said they were in Key West, Florida when Hensley decided to leave him and join an unidentified Australian couple who were sailing their boat around the world.
Felix stated Hensley had burned all her identification and said she wanted to become a different person and forget everyone she knew before. In a letter to her parents, Felix said the Australians were named John and Vanessa. A year later, however, he claimed their names were Frank and Sally.
Hensley has never been heard from again. She is a native of Bismarck, North Dakota, and she and Felix met in California and began seeing each other in 1970. They were reportedly involved with drugs. Photos of Felix are posted with this case summary.
Felix's first wife, Mary Elizabeth Horton Vail, drowned in Louisiana in 1962. A photo of Mary is posted with this case summary. They had one son, named William Felix Vail Jr. and called Bill.
Felix said Mary had fallen in the Calcasieu River while they were running trotlines at night, but Mary was afraid of water, that section of the river was unsuitable for trotlines, and authorities found the trotlines still inside Felix's tackle box.
He was arrested for murder, held for three days and then released without charge, and the case was never put before a grand jury. Felix had $150,000 in life insurance on Mary, but only collected $10,000 from the insurance company because of the doubts about the manner of Mary's death.
Over 50 years later, a pathologist examined the autopsy report and found evidence of foul play, including large bruises on Mary's neck and legs and a scarf in her mouth. The pathologist believes Mary was forcibly asphyxiated and possibly struck with an oar before her body went in the river.
Bill, who was only eight years old, went to the police in California in 1970, after his father started seeing Hensley. He told them his father kept drugs in the house and had forced him to use them, and that he'd heard him confess to Mary's murder.
Felix was arrested for drug possession, contributing to the delinquency of a minor and child abuse as a result of Bill's report, and the child went to live with Mary's parents. Felix pleaded guilty to the drug charge and was sentenced to six months in jail. California authorities passed Bill's information on to the police in Mississippi, but they still found insufficient evidence to prosecute Felix for Mary's murder.
Felix married seventeen-year-old Annette Craver Vail
in 1983. Annette's mother, Mary Craver Rose, said her daughter and Felix fought constantly and Annette planned to leave him, but they later reconciled. Annette's family last saw her in Sulphur, Louisiana on October 5, 1984. Felix told the neighbors she had gone to visit friends in Colorado.
After Annette's mother reported her missing later that month, he told the police she'd taken a bus not to Colorado but to Mexico, saying she wanted to disappear. He stated she suffered from mental illness, and had taken about $50,000 in cash with her when she left.
The police didn't believe Felix's explanation of his wife's disappearance, but found no evidence of foul play. In December 1984, he filed for divorce, citing irreconcilable differences and desertion. He gave all of Annette's belongings and clothing to charity.
Rose was active in the search for Annette after her disappearance, contacting anyone who knew either Annette or Felix to ask if they had information, as well as hiring private detectives. She found out about Mary's death and Hensley's disappearance.
Felix wrote Rose a letter accusing her of slandering him. He wrote Annette had emotional problems stemming from Rose's bad parenting, called Annette a "zero image whore" and said he wouldn't reveal where she was even if he knew.
In September 1985, almost a year after Annette's disappearance, Felix told her mother she had contacted him. He said Annette told him she was traveling with two men among the "natives" in the jungle and had had a baby. No one besides Felix has seen or heard from Annette since October 1984.
The FBI began investigating Felix as a possible serial killer in 1993; it's statistically highly improbable that he would coincidentally have one wife and one girlfriend who disappeared, and one wife who died under suspicious circumstances.
They interviewed one of Felix's girlfriends from the 1980s and she said he was physically violent towards her and eventually she got a restraining order against him. The FBI closed the investigation the following year, however, without finding enough evidence to file charges.
Felix and Mary's son Bill died of esophageal cancer in 2009, at the age of 46. Before his passing he made a video statement of everything he claimed he'd heard his father say about Mary's alleged murder. One of Felix's neighbors from the 1960s said he had cursed his first wife and claimed he'd killed her because she was pregnant again.
The investigations into Mary's death and Hensley and Annette's disappearances were reopened in 2012 after Jerry Mitchell, an investigative reporter for the Mississippi newspaper The Clarion-Ledger, ran some articles on the case.
Felix was living in Mississippi at the time. When Mitchell tried to interview him about Mary and the missing women, he suddenly left the area, leaving some of his belongings behind.
In May 2013, Felix was arrested in Comal County, Texas and charged again with murder in Mary's 1962 death. At his trial, his attorney argued Mary's death was an accident, but three former friends testified that Felix had confessed to murdering her, and two forensic pathologists said Mary's case was a homicide.
In August 2016, nearly 54 years after Mary's death, Felix was convicted of her murder. He was sentenced to life in prison without the possibility of parole, and his conviction was upheld in 2018. In an interview given with the KPLC-TV news station, Felix claimed both Hensley and Annette were alive and he knew where they were but wouldn't say where because "they’re in the Felix Vail witness protection program."
Foul play is suspected in Hensley's disappearance. Louisiana police currently investigate her case.