Joseph Ambroz Sentenced in 1969 Murder of Mary Kay Heese Following Decades-Long Investigation

Joseph Ambroz Sentenced in Decades-Old Mary Kay Heese Murder

Joseph Ambroz was sentenced in July 2025 after pleading no contest to conspiracy to commit first-degree murder in connection with the 1969 death of 17-year-old Mary Kay Heese in Wahoo, Nebraska. The resolution followed multiple investigations spanning over five decades, culminating in a renewed effort by the Saunders County Attorney's Office. Wayne Greaser, who died in 1977, was identified as the other individual involved in the conspiracy.

The case of Mary Kay Heese's murder, unsolved for over 50 years, reached a conclusion with a plea agreement in 2025.

The 1969 Homicide of Mary Kay Heese

On March 25, 1969, Mary Kay Heese, a 17-year-old high school student, was reported missing after she did not return home from school in Wahoo, Nebraska. Witnesses reported seeing her enter a vehicle with two men around 5 p.m. at the corner of 12th and Linden streets.

Her school books and purse were found neatly stacked on a road near a field close to midnight. Her body was discovered in a nearby ditch. An autopsy determined she had been beaten and stabbed 14 times. Investigators found her shoes, tire tracks, and a size 9 1/2 shoeprint at the scene. No knife was recovered, and sexual assault was not reported.

Cousins of Mary Kay described her as a happy individual who desired social acceptance. She had expressed an intention to attend an upcoming Sadie Hawkins dance and had invited her cousin Jerry in a letter approximately one week prior to her death.

Initial Investigation Fails to Yield Answers (1969)

The initial investigation involved multiple law enforcement agencies. Investigators were unable to identify the individuals in the vehicle, and the case remained unsolved. Joseph Ambroz, then 22, was questioned and subjected to a polygraph test.

Ambroz, who was on parole for forgery and escape, worked at a slaughterhouse in Wahoo and was known to frequent the same café as Mary Kay, sharing mutual friends. He drove a white over blue 1956 Chevy, a car type reportedly seen near the crime scene.

Ambroz denied involvement and provided an alibi, stating he was with his friend Wayne Greaser. During questioning, Ambroz admitted to parole violations, leading to his incarceration for approximately one and a half years.

Prosecutors later noted significant challenges in the initial investigation, including a lack of a clear lead investigator, insufficient follow-up on evidence such as unexamined cars for blood, and a heavy reliance on polygraph tests.

Decades of Renewed Investigations

In 1999, the Nebraska State Patrol Cold Case Unit, led by Sgt. Bob Frank, reopened the case. Forensic testing for DNA and fingerprints on Mary Kay's belongings, including her schoolbooks and gloves, yielded no conclusive evidence. Sgt. Frank interviewed individuals who reported hearing confessions from both Joseph Ambroz and Wayne Greaser, although these were considered hearsay.

In September 1999, Frank interviewed Ambroz in Florida. Ambroz denied involvement, offered an alibi different from his initial statement, and provided a blood sample for DNA testing, which did not match any forensic evidence. Sgt. Frank noted that Ambroz's shoe size (9 1/2) matched a shoeprint found at the crime scene and observed his explanations for alibi changes as suspicious. The evidence was presented to the county attorney but was deemed insufficient for charges at the time.

In 2015, Ted Green, a criminal investigator with the Saunders County Attorney's Office, initiated a new investigation. Green consolidated reports from various agencies and reinterviewed witnesses. Green stated that a witness claimed Ambroz had expressed a desire to have sex with Mary Kay. Another witness reportedly saw Ambroz and Greaser arguing about a girl on the night of the murder. A co-worker recalled Ambroz stating, "I can do six months, but I can't do life," which Green interpreted as a potential motive to prevent Mary Kay from reporting a sexual assault attempt. Green concluded that Mary Kay would likely not have entered a vehicle with unknown individuals.

In 2019, a Facebook tipline, established by Mary Kay's cousin Kathy Tull and friend Josh Eberhardt, received a tip about men pushing a car resembling Ambroz's into a reservoir shortly after the murder. Green subsequently initiated a five-year process to search the reservoir, which included dredging. This effort yielded metal and fiber consistent with a car, but no definitive proof.

In 2021, Green interviewed Ambroz, who admitted to having blood on his car's left rear fender on the night of the homicide, claiming it was from hitting an animal. Green theorized this was Mary Kay's blood. In 2024, Mary Kay's body was exhumed for a second autopsy. The pathologist noted the stab wounds were consistent with techniques used in slaughterhouses, where Ambroz had been employed. Green also observed that the pattern of the crime scene shoeprint matched prison-issued shoes Ambroz might have worn while on parole.

Investigator Ted Green's persistent efforts over nine years led to critical new evidence, strengthening the case against Joseph Ambroz.

Arrest, Plea Agreement, and Sentencing

In 2023, Green presented his findings to the county attorney. A grand jury indicted Joseph Ambroz for first-degree murder. On November 18, 2024, Ambroz, then 77 years old, was arrested in Oklahoma and extradited to Nebraska.

In July 2025, Ambroz accepted a plea agreement, pleading no contest to conspiracy to commit first-degree murder. The agreement included Wayne Greaser as the other co-conspirator. Ambroz maintained his innocence but stated he accepted the plea due to health issues and a fear of not surviving a trial.

Due to sentencing guidelines from 1969, the maximum penalty for conspiracy to commit murder was two years. On August 27, 2025, Ambroz was sentenced to two years in prison. This sentence was subsequently reduced to one year under Nebraska's Good Time sentencing reduction law. With time served, Ambroz was released on November 15, 2025.

Mary Kay's cousins, Mark Miller and Kathy Tull, and investigator Ted Green expressed disappointment with the plea agreement and sentence, citing a lack of justice and unanswered questions. Ted Green retired immediately after the plea agreement.

"The family of Mary Kay Heese stated that their quest for justice remained unfulfilled."