Tammy Zywicki cold case: New DNA lead emerges in investigation

Illinois State Police announced they have a new lead in the 34-year-old cold case of a murdered college student.

They named a person of interest and are hoping the public can supply helpful information. 

State police say DNA was found at the crime scene and they’ve interviewed people connected. The person of interest died years ago. But police say the public can help solve this cold case. 

Killing of Tammy Zywicki

The backstory:

The murder of Tammy Zywicki in 1992 haunts law enforcement and the public every year at this time, when college students are heading to campus, just as she was. 

Tammy had dropped off her brother at Northwestern University and was on her way to Grinnell College in Iowa when her car broke down on I-80. 

Ten days later, her body was found, wrapped in a blanket off a highway in southwest Missouri. 

Police believed the killer could have been a truck driver. 

This new person of interest was known to hitchhike across the country and might’ve  known the truck driver. 

In fact, Theresa Belenske’s DNA was found on the blanket Tammy’s body was wrapped in, according to state police. She died in 2014. 

What they're saying:

Retired FBI Agent Ross Rice said his whole team at the time was dedicated to the investigation. Back then, modern technology was not available. 

"Her remains were found in an open field after 9 days, 10 days, we don’t know," Rice said. "DNA degrades quite rapidly when it’s exposed to the elements and that’s the situation here. Compound that with forensic investigators were just learning about DNA. They were just learning what to look for, how to look for, what to capture." 

Tammy’s parents kept the investigation in the public view until they passed away. Now investigators hope someone who knew Theresa Belenske in the 1980s and 1990s might recall helpful information. There is still a $50,000 reward for information that can help solve this case.