Police obtained an arrest warrant for Scott, but he has not yet been charged in the killing of 6-year-old Amarion Adams and the wounding of four others on Sunday, June 13.
Scott was booked on a probation violation and is being questioned in connection with the attacks.
Investigators believe Scott and 17-year-old Kendrick Jackson were looking for rival gang members when they drove up to a home on the 2000 block of West 14th Street. Police suspect one or both of the suspects opened fire into the crowd, striking the 6-year-old, Willis McDowell, 47, Sherman Brown, 49, Ronnell Waller, 47, and Steven Roberson, 41. Amarion Adams died at Loma Linda University Medical Center three days later.
Jackson has been charged as an adult with murder and attempted murder.