More than three decades after Tammy Zywicki vanished from Interstate 80 in Illinois, investigators have identified a new person of interest in her unsolved kidnapping and murder — a California woman who died in 2014 and who police believe may have once traveled with an unknown truck driver connected to the investigation. Zywicki, who grew up in Greenville, South Carolina, was 21 years old when she disappeared on August 23, 1992, while driving back to Grinnell College in Iowa.
Illinois State Police and the FBI announced the development this week, naming Theresa “Teri” Belenske, a onetime hitchhiker with ties to several Southern California cities, as the newly identified person of interest. Officials were careful to clarify that Belenske, who died in 2014 at age 54, is not a suspect in the crime, according to FOX Carolina News. Investigators believe she may have traveled with the unknown suspect before Zywicki's death, and they are asking anyone with memories of her from the 1980s through the mid-1990s to come forward.
Belenske had documented ties to San Bernardino, Vista, Oceanside, Fontana, and Pomona, California, and was known to hitchhike during that era. Illinois State Police special agents are seeking information about a person connected to the unknown truck driver, and investigators released a 2009 photo of Belenske as well as an AI-generated image depicting her possible appearance in 1992 to help jog memories.
What Happened on Interstate 80
Zywicki had left Evanston, Illinois, for Grinnell, Iowa, when her white Pontiac T1000 broke down on I-80 at mile marker 83 in LaSalle County. She was last seen between 3:10 p.m. and 4 p.m. that day, expected to arrive at college that evening. Her car was later found abandoned on the same stretch of highway and towed by Illinois State Police the following day, after her mother contacted authorities when Tammy failed to arrive at school.
Witnesses who spotted the disabled car reported seeing a semi-truck parked nearby with a distinctive faded, rusty orange stripe around its center, according to Wikipedia's account of the case. Police have described the unknown truck driver as a man between 35 and 40 years old, over six feet tall, with dark and bushy hair. Nine days after she disappeared, on September 1, 1992, Zywicki's body was discovered dumped along Interstate 44 in rural Lawrence County, Missouri — more than 500 miles from where her car broke down. An autopsy determined she died of seven to eight stab wounds to the chest.
A College Photographer Remembered
Before her death, Zywicki was an active student photographer at Grinnell College and had served as photo editor for the campus newspaper, The Scarlet & Black, in 1990, according to The Scarlet & Black. She was reportedly traveling back to campus early to photograph student-athletes for the college yearbook when she disappeared. Among her personal belongings never recovered are a Canon 35mm camera, a red and white soccer patch monogrammed with St. Giles Soccer Club, Greenville, SC, and a distinctive Lorus brand musical wristwatch featuring a green umbrella on its face that played the tune Raindrops Keep Falling On My Head, according to Shaw Local.
Decades of Dead Ends and Cleared Suspects
The case has produced numerous theories over the years, none of which have led to charges. A retired Illinois State Police investigator publicly asserted in 2014 that deceased long-haul trucker Lonnie Bierbrodt was the primary culprit — he had been questioned in 1992 and allegedly gifted someone a musical watch similar to Zywicki's missing property — though police never found enough physical evidence to charge him before his death in 2002, per CBS Chicago. Illinois State Police also formally cleared convicted serial killer and former long-haul trucker Clark Perry Baldwin as a suspect in May 2020, after investigators examined possible links to his 1990s interstate homicides in Tennessee and Wyoming.
The pattern of truckers linked to highway killings is not unique to this case. The FBI's Highway Serial Killings Initiative, established in 2004, has linked long-haul truckers to more than 850 homicides and identified roughly 450 potential suspects across U.S. highway corridors, according to Texas Public Radio.
Modern DNA Testing and a Renewed Reward
Illinois State Police and the FBI are actively retesting more than 200 pieces of evidence collected during the original 1992 investigation, using DNA technology that did not exist at the time, including items such as duct tape, shoelaces, and a blanket found wrapped around Zywicki's body. The FBI has reaffirmed an active reward of up to $50,000 for information leading to the identification and conviction of whoever is responsible for Zywicki's kidnapping and murder.
According to the National Institute of Justice, agency funding helped the Boston Police Department solve a rape and murder case almost 50 years after the crime, illustrating how modern forensic methods can reopen long-unsolved cases. NamUs, the federal database for missing and unidentified people, lists 15,537 unidentified persons in its reports and statistics.
Officials are asking anyone with information about Zywicki's killing or about Belenske's travel companions to submit a tip through the Illinois State Police crime-tip website or by calling the FBI tip line at 1-800-CALL-FBI. Investigators have released photos of Zywicki and her missing property alongside the images of Belenske in hopes that, more than 34 years later, someone's memory can finally close the gap between a broken-down car on I-80 and the driver of the truck parked nearby.
