ROMULUS, N.Y. (AP) — The mother of one of the victims of the mass shooting at the Gilroy Garlic Festival held tight to a framed photo of her son as she left his funeral on Thursday.

Services for 25-year-old Trevor Irby were held at Romulus Central School in central New York, where Irby graduated from in 2012.

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He was one of three people killed at the festival July 28.

Tammy Williams, left, holds a photo of her son Trevor Irby, 25, as she and her husband Will leave a funeral service in Romulus, N.Y., Thursday, Aug. 8, 2019. Irby and two others were killed July 28 at the popular Gilroy Garlic Festival. (AP Photo/Adrian Kraus)

Tammy Williams, left, holds a photo of her son Trevor Irby, 25, as she and her husband Will leave a funeral service in Romulus, N.Y., Thursday, Aug. 8, 2019. Irby and two others were killed July 28 at the popular Gilroy Garlic Festival. (AP Photo/Adrian Kraus)

The funeral for 13-year-old Keyla Salazar was held Tuesday in San Jose. Also killed was 6-year-old Stephen Romero of San Jose. More than a dozen other people were injured when Santino William Legan opened fire with an assault-style rifle.

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Earlier this week, the FBI announced it was launching a domestic terrorism investigation of the shooting.

Irby graduated from Keuka College and was working as a medical technician in Scotts Valley.

Pallbearers at his funeral wore jerseys of his favorite Pittsburgh Steelers.

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© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.