Garza was shot and killed on Sunday while working at an American Canyon Safeway.
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"I didn't get to speak to him, see him, hold him or hug him in for a while. Now I can't," said Tracy Garza, Nathan Garza's mom.
Tracy Garza flew back from helping her daughter in Texas to the news of her son's passing. She described him as her miracle child.
"We waited for him for a long time. He was the youngest of six older sisters. He was our only boy and he filled the room, he filled our lives," said Garza.
On Sunday, around noon Garza was working at a American Canyon Safeway when a suspect drove up, shot him and fled the scene.
A 9-11 call describes, "We are getting multiple calls, three shots heard in the parking lot. There is a subject down on the ground"
According to his coworkers, Garza was simply doing his job delivering groceries in the parking lot.
"There is nothing that can explain what happened or justify it. It was senseless," said Tracy Garza.
Less than 24 hours after the fatal shooting Napa County confirmed 23-year-old Christopher "Roly" Young from Martinez was arrested and charged with murder.
"I want to thank the Napa Police Department. I want to give them my love. They don't get a lot of thanks right now during these times but they deserve more than what they are getting," said Gabriel Garza, Nathan Garza's dad.
Outside of Garza's home, his High School friends filled a book with notes for the kind-hearted baseball player who dreamed of going pro one day.
"I just wrote him a message about all the interactions that we had and the impact he had on my life," said Asha Abd.
At Safeway his co-workers left candles and balloons to remember him, and held a vigil in his honor.
His family is still searching for answers.
"He was good to people, people loved him and we miss him," said Tracy Garza.