Tammy’s Terrible Trek – The Tammy Zywicki Case

Photo courtesy of Murders, Missing People, and more Mysteries Facebook Group

Guest Post By Ian Granstra:

The July 2018 disappearance of 20-year-old Mollie Tibbetts made national headlines. When the University of Iowa student’s remains were discovered shortly over a month later, people across Iowa and America were devastated. It is still hard to fathom how an All-American girl in the prime of her life was killed by a man she had never met. Sadly, Mollie’s was not the first horrific murder involving an Iowa coed.

On September 1, 1992, 21-year-year Grinnell College student Tammy Zywicki met a similar fate. Nine days after she was last seen, her remains were found in southwest Missouri. Both girls attended colleges in Iowa, and they were petite, attractive women in their early twenties. Each victim was stabbed, and neither knew her assailant. There is one significant difference between the brutal deaths of these two young women. A suspect has been arrested and is awaiting trial in the murder of Mollie Tibbetts. After 27 years, no one has been charged with the slaying of Tammy Zywicki.

 Zywicki hailed from New Jersey but was attending college in Grinnel, Iowa. Her brother Darren was a student at Northwestern University in Evanston, Illinois. On Sunday, August 23, 1992, Tammy drove her brother to his dorm room. She departed Evanston that afternoon en route to Grinnell where her classes for the 1992-93 school year began the following day. The distance between the two schools is just under 300 miles, and Tammy planned to arrive in Grinnell that evening. 

 In the late afternoon of August 23, an Illinois state trooper found a 1985 Pontiac T1000 abandoned at the side of Interstate 80 near LaSalle, Illinois, approximately 100 miles southwest of Evanston. He assumed the car had mechanical difficulties and that the occupant had pulled to the side of the road to fix them. The following day, after finding the car still sitting beside the highway, the Illinois State Police towed the vehicle. The car with New Jersey license plates turned out to be Tammy Zywicki’s.

Photo courtesy of Murders, Missing People, and more Mysteries Facebook Group

The Illinois police soon received a call from a concerned woman in Marlton, New Jersey. JoAnn Zywicki told them her daughter had not arrived in Grinnell as planned. A sinister scenario was unfolding. An attractive college girl was missing, and her car abandoned along the side of a busy highway. Authorities feared the worst. Nine days later, those fears were confirmed.

 On September 1, Tammy’s body was found in a ditch off Interstate 44 just east of Sarcoxie in Lawrence County, Missouri, 22 miles east of Joplin. She was bound in duct tape and wrapped in a red blanket. An autopsy determined Tammy was sexually assaulted and stabbed eight times. The location of Tammy’s remains was approximately 500 miles from where the car was discovered.

 Several motorists traveling along Interstate 80 on August 23 came forward saying they saw Tammy standing near her car at mile marker 83 near LaSalle in north-central Illinois. These sightings were all believed to have been between 3:10 and 4 p.m. The witnesses also recalled seeing a white tractor-trailer parked near Tammy’s car. It was described as five-axle with rust-colored diagonal stripes on the trailer and cab. A logo was juxtaposed over the lines, but no one could recall from which company.

One witness recalled seeing Tammy standing beside her car on the shoulder of the Interstate. The car’s hood was open, and an agitated Tammy appeared to be struggling to fix the problem. A man was standing near the vehicle, watching as Tammy played mechanic. He was described as 35-40 years old, white, and at least six feet tall with dark, bushy hair. 

A September 1992 Des Moines Register article stated the witness who reported seeing the man was a male trucker, but later reports say the witness was a female nurse. The nurse also reported that a woman came for a blood test to the medical facility where the nurse worked that same day of August 23. The patient said her husband was a trucker and that he had recently given her a musical watch. The description matched that of a watch Tammy possessed when she left Evanston and which has not been found. 

 The long-haul truck driver and possible serial killer Bruce Mendenhall is a person of interest in Tammy’s murder. 

Photo courtesy of Murders, Missing People, and more Mysteries Facebook Group

In 2007, Mendenhall was arrested for the murder of 25-year-old Sara Hulbert in Tennessee. Subsequently, his truck was examined, and the blood of several murdered or missing women was found in it. None of the blood, however, was determined to be Tammy’s. 

Mendenhall was convicted of Sara Hulbert‘s murder In 2010. He has also been charged with the murders of three other women at truck stops in Indiana, Tennessee, and Alabama. He is also a suspect in the murders of women in New Mexico, Texas, Oklahoma, Georgia, and his native Illinois. Mendenhall is currently imprisoned in Tennessee. 

One source I found says Mendenhall has been ruled out as a suspect in Tammy’s murder because it was proven he was not in the midwest at the time. Other sources, however, say he has not been officially cleared.

 The name  that is mentioned most frequently as the possible killer of Tammy Zywicki is that of another long-haul trucker, Lonnie Bierbrodt. He had been sentenced to three concurrent twenty-year terms in prison for two armed robberies and attempted murder but was somehow paroled in 1990. 

Photo courtesy of Murders, Missing People, and more Mysteries Facebook Group

In addition to his violent past, many investigators consider Bierbrodt the prime suspect in Tammy’s murder because he had been visiting family who lived only a few minutes from where Tammy was last seen in Illinois, and he lived near where Tammy’s body was discovered in Missouri. Also, the red blanket covering Tammy’s body bore a Kenworth logo; Bierbrodt drove a Kenworth truck which he had steam-cleaned and sold shortly after Tammy’s murder. 

Articles state authorities identified Beribrodt as the man seen with Tammy, that he was questioned, and that he provided blood and hair samples. Bierbrodt died in 2002 at age 41. Several newspaper articles state that the nurse at the medical facility identified the man she saw as Bierbordt, and that police determined he was the man seen with Tammy along the side of the Interstate. 

Robert Kotlarek is a member of our group and also operates the Facebook group, “Who Killed Tammy Zywicki.” He clarifies this point below. This information was told to him by Martin McCarthy, the now-retired lead detective in investigating Tammy’s murder, and Tammy’s mother, JoAnn: 

“The bushy-haired, semi-truck driver has gotten conflated with Bierbrodt over the years. Like the old “telephone” game children play (or once played), the information has gotten distorted. The nurse witness reported seeing a green pick-up truck and a man with “short brown hair” that was possibly “thinning on top.” She later (December of 1992) thought that Lonnie was the man she saw on the side of the road. Bierbrodt’s wife Carrie did own a blue pick-up that was sold after Tammy was murdered. The nurse witness never mentioned a semi-truck in her initial interview with police, and as far as we can tell Bierbrodt was not driving a semi in Illinois on August 23, 1992. So basically, the “bushy-haired” truck driver and the nurse witness’ description of the man that matched Lonnie Bierbrodt are from (at least) two separate accounts.” 

Join Robert’s group, “Who Killed Tammy Zywicki.” https://www.facebook.com/groups/71031476920/?hc_location=ufi


The FBI still features Tammy’s case on its website and continues to offer a $50,000 reward for information leading to the identity of her killer. Also, a separate $100,000 reward is being provided by an anonymous person or group from Tammy’s hometown of Marlton, New Jersey. The FBI has DNA evidence obtained from Tammy’s body, which they believe will lead to the killer’s identity. 

If you have any information about the murder of Tammy Zywicki, please contact the Illinois State Police at (815) 726-6377 or the Chicago FBI Field Division Office at (312) 421-6700.

THIS LIST OF LINKS IS NOT AN ALL-ENCOMPASSING SOURCE CITING. ALL OF THE INFORMATION USED IN THIS ARTICLE CAN BE EASILY FOUND ONLINE. LINKS BELOW WERE USED AS SOURCES AND ARE RECOMMENDED READING FOR SYNOVA’S READERS. Synova strives to cite all the sources used during her case study, but occasionally a source may be missed by mistake. It is not intentional and no copyright infringement is intended.

Further Reading:


Chicago Tribune


More About Our Wonderful Guest Blogger:

Ian Granstra

Ian Granstra is a writer and a native Iowan now living in  Arkansas.
Growing up, he enjoyed watching real-life crime shows and further researching the stories featured. He wrote about many of them on his personal Facebook page, and several people suggested he should start a group featuring his writings. Ian founded the Facebook group “Murders, Missing People and More Mysteries”  in August of 2018 he writes about many cold cases. The group also features many current crime cases in the news.
When Ian isn’t writing, he enjoys exercising, traveling and collecting sports cards. He’s also a big animal lover (his Facebook nickname is “beaglelover.”)


This week’s Recommended Reading:

The Face of Evil: The True Story of the Serial Killer, Robert Black

The Happy Face Murderer: The Life of Serial Killer Keith Hunter Jesperson

If you enjoy this content don’t forget to sign up for Synova’s Weekly True Crime Newsletter. You will receive exclusive content directly in your inbox. As a gift for joining you will also receive the Grim Justice ebook free.



All information used to create this content is a matter of public record and can be easily found online or can be verified by the guest blogger. Any participation or alleged involvement of any party mentioned within this site is purely speculation. As the law states, an individual is innocent until PROVEN guilty. I do not own the photos used in this post. All photos are used under the fair use act. No copyright infringement intended. Any and all opinions are that of the guest blogger and don’t necessarily reflect the views of Synova Ink©2017-2019. All rights reserved.

If you’d like to check out Synova’s true crime books follow this link to her Amazon Author Page.

Synova’s Amazon Author Page

81XSqT-n3BL._AC_UL320_  41d90mk2i0L   wp-image-675446049 seriously-stupid-box-set.jpg  

Click on the pictures to read more about each title and order your copy!

Synova’s Swag Store is now open check out her new merchandise by clicking on the Shop! link at the top of this page!

Come Quick!


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s