Sheila Leigh Walsh was born October 19, 1962, in Topeka, Kansas. She married Allen Blackthorne in 1982; the couple had two daughters, Stevie and Daryl, before divorcing in 1987 in a contentious split that included mutual accusations of child abuse. Sheila later married Jamie Bellush in 1993, and the couple had quadruplets two years later. The family relocated to Sarasota, Florida, reportedly to escape ongoing surveillance and harassment from Blackthorne, who had allegedly stalked her since the divorce and had reportedly been abusive toward his prior two wives before allegedly doing the same to Sheila.
Blackthorne remained unhappy about losing custody following the divorce and continued to harass Sheila. After the Bellush family moved to Florida, he used a private investigator to locate her and arranged to have her assaulted. He approached Daniel Alex Rocha, a golfing acquaintance, allegedly telling him that Sheila was abusing the two children from the marriage. Rocha contacted Samuel Gonzales, who introduced him to his cousin, Jose Luis Del Toro, who agreed to carry out an attack for $14,000.
On November 7, 1997, Del Toro traveled to Sarasota, purchased camouflage clothing, and made his way to the Bellush home. A neighbor spotted him and recorded his license plate, which later led to his identification. Del Toro broke into the home and encountered Sheila with the quadruplets; he later told police he nearly abandoned the plan after seeing her caring for the children, but when she noticed him, he shot her in the face with a .45 caliber gun and cut her throat in front of the children. Her body was discovered hours later by her 13-year-old daughter, Stevie, returning from school. The quadruplets, some wearing life vests Sheila had put on them, were found with blood on their feet from walking through the crime scene.
Del Toro fled to Mexico following the murder and was extradited to the United States in July 1999. In 2000, he pleaded guilty in Florida to first-degree murder and armed burglary and was sentenced to two consecutive life terms by Circuit Judge Paul Logan. Gonzales pleaded guilty to conspiracy to commit murder in June 1998 and received 19 years in prison. Rocha went to trial and was convicted of first-degree murder in January 1999, receiving a life sentence. Allen Blackthorne was convicted on federal charges of interstate conspiracy to commit murder and interstate domestic violence, receiving two concurrent life sentences without parole. He was later nearly killed in a prison attack in 2001 and was eventually transferred between facilities before dying at a federal prison in Terre Haute, Indiana, on November 18, 2014; the cause of death was not released.
The case was the subject of Ann Rule's book Every Breath You Take and has been covered in several true-crime television programs.