Investigators believe Uniese Brown, Christopher Stanley, Demarion Hackett, and an unnamed 16-year-old boy killed Anthony Calderon.
He was 22.
"My son was an amazing boy," Stephanie Tellez said.
"Very motivated. Inspired. Just smart and a well-mannered kid."
Calderon had plans to become a police officer, but those dreams were shattered on Thanksgiving morning.
Police say Anthony was smoking with two friends when several others approached his central Fresno apartment, firing more than 50 rounds.
"I can tell you it was unprovoked and nothing short of what we would categorically say was an ambush," Fresno Police Lt. Paul Cervantes said on February 11.
Gang enforcement detectives helped piece together the crime, eventually arresting four people.
Brown and Stanley are 19 years old, and Hackett is 20.
One after one, the three adult defendants each pleaded not guilty on Thursday.
Their attorneys told the judge they deny all the charges against them.
"I feel like we've got the people, and things are going to be in our favor," Tellez said.
For now, the adult defendants remain in jail on bail of over $3 million.
They are each due back in court next month, and Anthony's mom says she will keep wearing his picture over her heart.
"This is my son, so it's been devastating and really hard to deal with, as well as dealing with the trial and court process as well," she said.
Police confirm they are still searching for two suspects who they believe were also involved.
They say the victim and his two friends did not have gang connections.
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