(CBS) – Northwest Indiana authorities have charged a suspect in the mysterious murder of a Griffith, Ind. businesswoman who was found shot to death on a casino property late last month.

The body of Mary Austgen, a 76-year-old grandmother, was found in the parking garage of the Majestic Star Casino in Gary, Ind. on March 29. It’s believed the St. John, Ind. resident was abducted from her family business in Griffith, Ind. the day before.

On Thursday, police said 57-year-old Ralph Perez Martinez, of Alsip, was the person who killed Austgen. Perez, who was taken into custody earlier this week, was charged with murder, robbery and criminal confinement.

He previously had rented work space from Austgen but had been evicted for living there, police said. He allegedly stole two rings and $2,000 in cash.

Police say Martinez’s ex-wife turned him in after seeing news accounts that included a surveillance photo of a suspect police sought.

The former spouse told investigators when she and Martinez saw the picture on the news she said he looked like the suspect.

“That’s not me,” he reportedly replied.  “Lots of people with money get killed.”

When the news announced a $10,000 reward, the woman quoted Martinez as saying, “Is that all I’m worth?”

She also recalled seeing a ring in her bedroom that resembled one that police say had been stolen.

“We’re elated, we’ve had a lot of emotions the last several days,” the victim’s son, Jeff Austgen, said.

Martinez, held at the Lake County jail in Crown Point, Ind.,  could appear as soon as Friday in court.

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