Desmond Turner gave himself up at the Arrestee Processing Center, the Indianapolis Star reported. The newspaper said police radio chatter suggested that his family had convinced him to surrender.
Earlier Saturday, police used gas in a raid on a house, but found no signs of the suspect.
The 28-year-old Turner was on parole after serving time for criminal recklessness and weapons and drug charges.
He is charged in the city's worst homicide in more than 20 years.
Police arrived at the crime scene Thursday night after getting calls from neighbors who heard screams and gunshots.
The dead have been identified as Albert Covarrubias and Emma Valdez; their two sons, David, 8 and Alberto, 11; Emma's adult children, Magno and Flora Albarran; and Flora's son, Luis, 5.