"This does not appear to be a random act," Sgt. Shane Foley of the Indianapolis Metropolitan Police Department said during a Sunday press conference.
Metropolitan Police Department Chief Randall Taylor said the shooting, which occurred before 4 a.m. local time (09:00 GMT) on Sunday, was a "mass murder."
After police arrived at the site of the shooting, a home in Indianapolis, they found a juvenile male suffering from gunshot wounds footsteps away. Another five people, including a pregnant woman, were pronounced dead after being found in the home. The unborn child did not survive.
"The juvenile male who was shot is expected to survive his injuries," Sgt. Shane Foley said.
An investigation is underway, but there is currently no information on suspects or the motive behind the shooting.
Indianapolis Mayor Joe Hogsett also called the shooting a "mass murder" and said that local, state and federal law enforcement are involved in the manhunt.