It's where a police officer was found dead on or near a rock in some grass next to gas pumps. Some believe he committed suicide but others feel that someone murdered him out there.

Captain Mike O'Mara

Captain Mike O'Mara

Thanks. Has his case been solved?

Thanks. Has his case been solved?

Not according to the wiki... :(

http://unsolvedmysteries.wikia.com/wiki/Mike_O%27Mara

Barbara O'Mara recalls that on the last day of her husband's life they were sitting around after dinner when he announced he had an errand to run. He asked if she and their two children wanted frozen yogurt, borrowed a few bills from Barbara's purse, and said he would pick up some on the way home.

O'Mara went to the nearby offices of P.S.I., a private security firm he ran in his off hours, driving a squad car permanently assigned to him as a ranking officer in the Sheriff's Department. He dropped off some paperwork and radioed the sheriff's office, telling a dispatcher to put him in service. Then he drove to a parking lot at the Markham Courthouse, where there is a gas pump reserved for county-owned vehicles.
http://articles.chicagotribune.com/1994-02-16/features/9402160107_1_ranking-officer-police-department-recalls

http://www.ipsn.org/omara.php

http://articles.chicagotribune.com/1988-06-02/news/8801040274_1_administration-division-degree-in-criminal-justice-cook-county-sheriff