Wilson Barajas told relatives he was going for a walk Saturday at McKinley Park, then disappeared. So that's where his loved ones focused their search.
Barajas recently graduated from UIC after earning two masters degrees.
Police say it appears his cell phone has been turned off. Family members say its unlike him to not contact them.
"This is very uncharacteristic. Wilson was never the type of person to make his family members worry. He talked to his mother every day. Always kept in touch. So this is very unlike Wilson," said Samuel Barajas, cousin.
Police say tips are coming in very slowly. Relatives tell ABC7 Barajas had not been feeling well several days before he vanished.