Austgen's brother has seen the surveillance photos of the man police want to talk to. He said he does not recognize the man at all, but he hopes that someone does recognize him and comes forward.
"Right now, he left with her, so I think because of that we would like to speak with him. I do not want to rule him a suspect until we speak with him," said Griffith Police Detective Lt. Matt Argadine.
Police say photos were taken at Austgen's family business, where surveillance cameras cover the property in Griffith.
The man, in sunglasses and a Harley hat, was captured walking through the front door. Police showed the pictures to people who rent property from Austgen.
"I sat there and stared at the picture," said renter Mick Drwal. "You want to recognize the guy, and then you don't, you feel so helpless."
After seeing the pictures, Austgen's brother, Jack Reder, told ABC-7, "I'm a religious person. I don't have any hate. I just want justice served and whoever did it found."
Police say Austgen was abducted from her business Thursday. Her body was found before sunrise Friday at the Majestic Star Casino. She had been shot and was in the passenger seat of her 2011 GMC Yukon Denali.
"We're not for sure if she was killed at that location or driven to that location," said Gary Police Chief Wade Ingram. "We are waiting for lab results from the laboratory."
Though Austgen lived in St. John, she had a long-time reputation in Griffith.
"Mary and her husband were prominent business people in town," said Glen Gaby, Griffith Town Council president. "They have a lot of property, they have a lot of businesses, they employ a lot of people."
And the loss reverberates throughout town.
"Griffith is a quiet community. It's shocking for us to deal with and our hearts go out to her family," said Rick Ryfa, Griffith Town Council.
Police do not believe that this was a random act of violence, and it does not appear that Austgen or the man in the photos were in the casino at any point.