The driver was sentenced to just four years in jail.
A woman who lost her three children has been arrested for striking their killer.
Brittany Ingle was led out of an Indiana courthouse in handcuffs on Wednesday during the sentencing of Alyssa Shepherd, the reckless driver who ran over 9-year-old Alivia Stahl and her twin 6-year-old brothers Mason and Xzavier Ingle.
The crash happened in the early hours of October 30, 2018, when the siblings were crossing the road outside their rural home in Rochester to board a school bus.
Although the bus had its stop arm extended and lights flashing, Shepherd failed to stop her pick-up truck and hit four children. Only 11-year-old schoolmate Maverik Lowe survived.
In October of this year, the 25-year-old was found guilty of three counts of felony reckless homicide and one count of criminal recklessness, as well as the misdemeanor of passing a school bus with stop arm extended and causing injury.
Although she faced a maximum sentence of 21.5 years in prison, she was sentenced to just four — and it was too much for the bereaved mother.
She lunged at Shepherd in the courtroom, and "was able to get close to her and struck her in some way, either with her hand or elbow, maybe in the face or head area," Fulton County Prosecutor Michael Marrs relayed to WNDU.
"Probably going to be a battery charge coming out of that," he added. Ingle was charged preliminarily with misdemeanor battery.
The deceased children's grandfather Michael Schwab said: "We all feel as a family that the death of killing three children should have been a more stringent penalty, but we are glad she is going to get some time served."
"There's a lot of different talk, but children still remain our greatest gift. If we aren't going to protect them and hold people accountable when they get hurt, then we may as well just get rid of the laws. They aren't going to be worth anything if we don't execute them and hold people accountable."
During the trial, Shepherd described the morning of the crash, claiming it was pitch black outside. She said she saw the flashing lights in the distance but didn't realize they were from a school bus.
Her lawyers pushed for a fully suspended sentence with no jail time, arguing her own two young children would be affected. In the end, Shepherd was sentenced to four years behind bars, followed by three years house arrest, and three years probation after that. Her drivers license was also suspended for ten years.