Tom Fallis, 34, had moved to Bloomington with his children shortly after his wife’s death.
The shooting happened around 10:38 a.m. in the 4400 block of North Franklin Road.
Police say the victims report their barns or other out buildings had been broken into.
Police said the suspect owed money to the the dead man in the trunk.
Mayhew pleaded guilty last month to felony counts of narcotic possession and neglect of a dependent.
Officers made the discovery at the Budget Inn Motel on West Main Street after they were dispatched for the report of a battery.
Her name was Domina, and police want to catch whoever killed her before they target a person.
Witnesses called police around 11:50 Sunday evening, saying they saw a man slashing tires in the area.
A Lake County court has scheduled a Dec. 5 hearing on the request for a DNA mouth swab from 43-year-old Darren Vann of Gary.
Officers are searching for the suspect in an armed robbery at the Taylorsville branch of Centra Credit Union.