Coles was in the Lubbock County Jail on Thursday, with bail set at $500,000.
Electronic jail records had no attorney listed for Coles, who was booked early Wednesday over the death of 11-month-old Shawn Patrick Smith. An autopsy determined the boy suffered blunt force injuries.
Coles was indicted Tuesday by a Lubbock County grand jury. Prosecutors have not said whether they will seek the death penalty.