Forty-six-year-old Lester Hobbs and 7-year-old Aja Johnson were last seen Saturday night in Geronimo — about 100 miles southwest of Oklahoma City.
Hobbs is charged with first-degree murder in the beating death of the girl's mother, Tonya Hobbs, whose body was found Sunday.
The Oklahoma State Bureau of Investigation and the U.S. Marshal's Service are offering the reward for information leading to Hobbs' capture.
OSBI spokeswoman Jessica Brown says a reported sighting of the dead woman's missing white 1992 Toyota Paseo in Oklahoma City is believed to be bogus.Previous coverage