Police said 24-year-old Monique Marlow was cleaning out a car at the business on Satellite Boulevard in the Atlanta suburb of Duluth when she was shot in September 2012.
Hertz had been offering a $25,000 reward for information leading to the arrest and conviction of the killer. The company announced this week that its reward will be doubled to $50,000.
Marlow's family believes one key to finding the killer could be a missing sliver necklace Marlowe often wore. The necklace includes a mouse ear pendant.
Police have had few leads. Her father believes robbery might have been the motive.
Marlow was a 2009 University of Georgia graduate.
http://accesswdun.com/article/2013/10/266892