Lassiter was a freshman and a starter football player on the junior varsity team at the high school. He was also a special needs student.
"I didn't know him that well, but he was sweet, he was really gentle, just a shame that he did that," said student Adriana Dodge.
On Monday, some students wore black T-shirts with Lassiter's football number 51 on it.
"I'm on the football team, and he was on the football team, and we're taught that we're family on and off the field, and losing Jeremiah was like losing a brother," said student Zac McGuire.
According to students and campus officials, Lassiter was constantly picked on by the other kids. His older brother also attends the school.
"He was about 6 feet 4, very big guy, and he never laid a hand on anybody, at least not that I ever heard of or saw, and I saw kids push him to the limits," said teacher Roman Moretti.
Investigators are unsure where Lassiter got the gun, and they have not determined why he killed himself.
Classmate Paige Cummings said the day of Lassiter's suicide, kids were throwing food at him.
"One of the kids that is here stood up for him, and basically told the other kids throwing things, told them off, told them to stop," Cummings said.
A candlelight vigil was held in his honor on Monday night.
Some parents said bullying is a big problem at the school that needs to be addressed.
"I have a special needs daughter that's also in the school district. She's supposed to be here at this high school, and we won't allow her to come here because I just don't think it's safe. If they can't control the bullying and the picking on at the elementary schools or the junior high school, I can't have her come here," said parent Lisa Alonso
Sheriff's homicide detectives are investigating the death.
Grief counselors are on hand at Vasquez High School in Acton after a student suicide. The school enrolls about 580 students.
The superintendent of schools in Acton said they have a no tolerance policy on bullying, and if cases are brought to their attention, they deal with it.
"I think it's a terrible experience, but it's also a learning experience for all of us," said student Breanne Aronin.
"What you say really does matter."
Eyewitness News reporters Amy Powell and Leslie Sykes contributed to this report.
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