The Indianapolis teenager accused of killing six people at his family’s home, including a pregnant woman and her unborn baby boy, had been scolded by his father shortly before the "mass murder," according to a recent report.

The 17-year-old is in custody after the Sunday morning killings, when he allegedly opened fire on the five people inside, according to police and local affiliate FOX 59. Charges have not yet been announced, although they are reportedly expected by Thursday.

INDIANAPOLIS JUVENILE ARRESTED IN 'MASS MURDER' THAT LEFT 6 DEAD, INCLUDING PREGNANT WOMAN, UNBORN BABY

Police received a report of a person shot just before 4 a.m. Sunday in Indianapolis, according to a press release from the Indianapolis Metro Police Department (IMPD). Officers arrived to find a juvenile male -- the suspect’s brother -- near the home with what appeared to be gunshot wounds, police and the report said.

"They killed my family," he said, according to FOX 59.

The surviving teenage victim later told investigators the suspect, his brother, was in trouble with his father, who was scolding him for going somewhere without asking his parents first, according to the report.

The young victim, when discovered by police on Sunday, had pointed officers to inside the home, where they found five people who had been shot and killed. Police later identified the victims as Kezzie and Raymond Childs, both 42; Elijah Childs, 18; Rita Childs, 13; and Kiara Hawkins, 19, who was pregnant with a child whom police have referred to as "Baby Boy Hawkins."

Responders rushed Kiara Hawkins to a local hospital, but neither she nor the baby could be saved, police said. The boy who officers encountered outside was also taken to the hospital, where he is expected to survive.

INDIANAPOLIS 'MASS MURDER' LEAVES 6 DEAD, INCLUDING PREGNANT WOMAN, UNBORN BABY

Police have not yet released the name and photograph of the suspect.

"While removing the alleged perpetrator of yesterday's mass murder from our neighborhoods does not bring back the lives senselessly lost, hopefully, it will bring us one step closer to healing as a community," IMPD Chief Randal Taylor said Monday.

"I am grateful to all of the IMPD officers and criminal justice partners who have worked tirelessly for the last 30 plus hours to bring justice for these victims, their friends and families, and our entire community."

The surviving victim reportedly told detectives he was downstairs with his parents when they heard gunshots, followed by his sister screaming, "He shot them." More shots rang out after that.

The victim’s brother then "came down the stairs with a draco gun, a handgun that shoots rifle rounds, and started shooting," according to the report.

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As the boy ran out of the home, his brother allegedly chased after him and fired more shots.

Police later arrested the teen suspect in Plainfield and he is in custody at Marion County Juvenile Detention center, FOX 59 reported. He is expected to be charged as an adult.

Fox New's Danielle Wallace contributed to this report.