75-year-old man sentenced to under 3 years in 1966 killing of 10-year-old girl

Decades after a 10-year-old Massachusetts girl was beaten to death, a man has pleaded guilty to involuntary manslaughter and was sentenced to under three years in prison.

The office of Hampden County District Attorney Anthony Gulluni said Thursday that 75-year-old Donald Mars of Bedford had changed his plea following his 2022 indictment in the 1966 death of Betty Lou Zukowski. He had previously pleaded not guilty to first-degree murder.

The young girl was reported missing on May 26 of that year. She had left her family's home in Chicopee after receiving a phone call she told her mother was from a friend.

Four days later, on Memorial Day, young boys who were fishing in the Westfield River in West Springfield when they found Betty Lou's body. She had been beaten and was covered with mud.

Investigators determined she had died from multiple blunt-force injuries to the head, a skull fracture and terminal drowning, prosecutors said.

Mars, who was 17 at the time, has been linked to the case since 1997, when multiple sources mentioned his name to the West Springfield Police Department.

Witnesses were interviewed that year. One was shown about 30 photos from a 1967 Chicopee Comprehensive High School yearbook, and Mars was one of two photos he said reminded him of the last person seen with Betty Lou, authorities said.

Mars' mother, who was 95 when she spoke with police, told them her son had admitted years ago to throwing a rock and killing a little girl.

Mars' ex-wife also told police he had experienced a nervous breakdown and told her in 1987 that he and an unnamed friend killed Betty Lou with a rock and "dumped" her in Robinson State Park.

"He repeated the contents of this private conversation with her to his parents, in her presence, a couple years after he told her," Gulluni's office wrote in a press release. "She said that his parents did not seem surprised by the information."

The same woman told police the class ring from Chicopee Comprehensive High School had a blue stone like one described by witnesses in 1966. She owned one, and she said Mars told her he previously had one, as well, but lost it.

Still, Mars was not arrested. The district attorney's office's unsolved homicide unit picked the case back up in 2021.

Detectives interviewed Mars — a Level 3 sex offender who was convicted in 1995 of child rape and assault and battery on a child under 14 — in July of 2022.

According to prosecutors, Mars became emotional at times, including after being asked about Betty Lou.

"I'm not crying because of Betty Lou. I'm crying about my whole life," he told police, according to the district attorney's office.

Authorities say he told multiple versions of the killing occurring in different places, giving the location of the girl's head injuries and then denying doing so.

Mars told police Betty Lou "hurt him more than he ever hurt her," according to prosecutors. He then acted out the crime, authorities say, making four downward strikes with his left arm and admitting to hitting the girl with a rock.

Mars was arrested in 2022 on a first-degree murder charge, pleading not guilty.

While prosecutors say Mars acted alone and killed Betty Lou by repeatedly striking her head with a rock, then disposed of her body in the river, he pleaded guilty to a charge of involuntary manslaughter.

"Sadly, Betty Lou's parents are deceased, and are not able to see Donald Mars answer for the brutality he inflicted upon their daughter," Gulluni said in a statement. "While neither solving this case nor any punishment of the perpetrator will give Betty Lou a chance to live the life that she deserved, I hope today represents a significant step for her family in their mourning and how they are able to memorialize her, so many years later."

A Hampden Superior Court judge accepted his guilty plea, sentencing him to 30 months in prison and two years of probation. He is also required to register as a Level 3 sex offender.