Shelton Curtis, 22, was charged with two counts of murder in the shooting deaths of James Powell and Raymond Washington-Whitehead.
Powell, of the 2400-block of Whitcomb Street in Gary, and Washington-Whitehead, of the 8600-block of Illinois Street in Merrillville, were two of seven people killed in Gary in seven days.
Their bodies were found at a home in the 1100-block of Lane Street in Gary on Aug. 6.
Curtis was on the run and considered armed and dangerous. He turned himself in on Tuesday.
Curtis' alleged accomplice, 22-year-old Kevin Blackmon, was also arrested in connection with the double homicide. He is charged with assisting a criminal.
The Sun-Times Media Wire contributed to this report.