Timar's brother and a friend reported her missing Thursday.
Pat Barry is a spokesman for the Will County sheriff's department. He says the suspect and Timar were acquaintances and evidence suggests the death occurred in the suspect's residence.
Authorities say a motive isn't clear. Timar's body was found Friday morning in a vehicle abandoned on the side of the road in unincorporated Frankfort Township.
(The Associated Press contributed to this report.)
