A 16-year-old Napa boy has been charged with murder in Tuesday's fatal shooting of Robert Ratto, 19, of Napa. Police have not released the name of the suspect -- being held in Napa County Juvenile Hall -- because he is minor.

Ratto, a 2006 graduate of Vintage High, was pronounced dead when paramedics responded to a report of a shooting around 5:30 p.m. Tuesday at an apartment complex in the 300 block of Collier Boulevard.

He, along with the suspect and another 16-year-old boy, was sitting in a parked car in the apartment complex parking lot, Napa Police Cmdr. Steve Potter said.

Ratto was sitting in the passenger seat, one of the boys was in the driver's seat and the other in the back seat. The gun went off and one bullet struck Ratto in the torso, Potter said. The two boys carried Ratto to an apartment in the complex, where paramedics found him mortally wounded.

"The boys were friends," Potter said. "When officers first arrived they told them there had been a confrontation in the parking lot and the victim was shot. After talking to the boys, it was learned there had been no confrontation."

Witnesses and neighbors also said they did not hear or seeing anything relating to a fight.

Ratto's mother, Linda Smernes, remembers her son as "exceptional, very social with a lot of friends. He worked very hard to graduate last June and was very proud of himself. It was difficult for him," she said. "He was a hard worker. He would never just ask for money. He would do chores to earn it. He was just the sweetest kid with a gentle spirit. After he graduated he was looking forward to going to a training program to learn a trade. And now he's gone."

Potter said at this time investigators do not know where the teens got the gun, which detectives have recovered. The suspect was taken to the police station from the scene, interviewed and arrested.

Although Potter declined to discuss details of the interview, he said detectives gathered enough information to charge the youth with homicide.

Potter said the three boys were just hanging out together before the shooting happened. "There is no indication that there was any trouble among them prior to the shooting."

The homicide does not appear to be drug or gang related, Potter said.

In addition to the homicide charge, the suspect is also being held on charges of possession of a controlled substance and possession of a controlled substance for sale.

About 120 friends, teachers and family members met at Solomon park near Vintage High School Wednesday evening for a candlelight vigil. Mourners of all ages formed a grief circle, celebrating Ratto's spirit and sense of humor. The crowd shared stories of Ratto's life and his impact on them. Longtime friend Joseph Trefry, 21, lamented not being more of a mentor to Ratto. One teacher demonstrated Ratto's signature move, "the dance." As the sun went down and the moon rose, the mourners, several wearing T-shirts bearing Ratto's picture, with "In loving memory" and "Rob Rat" printed on the shirt, lit candles and hugged their loved ones.

Ratto was born in Berkeley and came to Napa in 1995.

In addition to his mother, Ratto is survived by his sister, Renae McCurdy of Napa, and brothers Anthony Smernes of Vallejo and Daniel Smernes of Eugene, Ore.