BOSTON (CBS/AP) — Two men convicted in the shooting death of an innocent bystander at a Dorchester street festival in 2014 have been sentenced to life in prison.

Keith Williams and Wesson Colas were sentenced in Suffolk Superior Court on Monday after being convicted of first-degree murder last month in the death of 26-year-old Dawnn Jaffier.

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Prosecutors say the men were rivals who confronted each other with guns near a Caribbean festival in Dorchester and that Williams fired the shot that killed her.

Colas was also found responsible because he participated in the shooting even though he didn’t fire the fatal shot.

Jaffier was a Boston Public Schools graduate who returned to the district to work as an after-school tutor and a coach at Playworks, a community organization. She also worked as a lunch monitor at the Hennigan School.

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Her brother said during Monday’s sentencing hearing that his sister’s death has changed his life forever. “Maybe someone watching this trial will put their gun down and I think that’s a win in itself,” her brother Ian Jaffier Jr. said.

Her father lamented that he will never see his “superstar” again.

“My daughter was a teacher, a college grad and coach,” Ian Jaffier said. “Making a positive impact on her students and her life was senselessly loss to gun violence.”

Ian Jaffier said men “walking around toting guns” should put them down, “instead of going around shooting people, try to be somebody. Make your family proud. Make your community proud.”

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)