The shooting happened at a home on Westside Boulevard just off of Highway 99, north of Atwater.
Deputies say gang members opened fire Saturday night, shooting five people. Three teenagers died from their injuries.
Deputy Delray Shelton said, "Our hearts do go out to the families and they're going to spend a long while picking up the pieces."
One of the victims was 16-year-old Samantha Parreira. Merced Unified's superintendent says she attended Golden Valley High School before transferring to the Yosemite High Continuation School about two months ago. Authorities say four young men were also shot. An 18 and 19 year old died, and a 21 year old and 16 year old are now recovering.
Deputy Shelton added, "It does seem like the ages of the victims and suspects are getting younger and younger, and that's unfortunate."
Detectives are now trying to track down the shooters, but it's difficult convincing witnesses to come forward.
Deputy Shelton explained, "Dealing with gang investigations there's always challenges, one being that people don't want to be labeled as "snitches."
The home where the shooting happened is next to a migrant housing complex. One woman who was visiting relatives there on Easter Sunday says her sister woke up to the sound of gunshots, and then a knock on her door.
Maribel Ureno translated what they said about the incident.
"My sister lives here and she said last night about 11 o'clock she heard some gun shots and she woke up and someone was knocking at her door. It was some young guy he was asking for help to get in. He was worried, crying and said someone got into their house and started shooting people. They were really scared because they didn't know what was going on."
Investigators say it's not clear yet if the victims had gang ties, but they do believe the suspects were trying to target their rivals.