Latasha Cheatum was just 18 years old when she was shot and killed in Detroit while driving on I-96 near Wyoming with her boyfriend in June 2010.
Cheatum was also about four months pregnant, according to her father who took out a mortgage on his house so that he could add money to the Crime Stoppers reward, making it $25,000.
An additional $1,000 will be added to the reward if Crime Stoppers receives the tip by midnight Tuesday.
"This cannot be forgotten," said Major Rush, Cheatum's father. "I just don't want to give up."
Click on the video to hear from Rush.
Anyone with information that leads to an arrest can remain anonymous by calling 1-800-SPEAK-UP.