​Arrests made in Halloween hit-and-run that killed 3 California teens

LOS ANGELES -- Police say they've made multiple arrests in connection with the Halloween hit-and-run deaths of three teenage girls who were trick-or-treating in a Los Angeles suburb.

Santa Ana police say officers made the arrests as of Sunday morning, but would not release details until a news conference scheduled for Monday.

Authorities say 13-year-old twin sisters, Lexi and Lexandra Huerta Perez, and their 13-year-old friend Andrea Gonzalez were struck and killed Friday night in a Santa Ana crosswalk, only two blocks from home.

Police say the driver of a black Honda SUV and a male passenger fled the scene without helping the victims. The damaged vehicle was found a short distance away.

CBS Los Angeles spoke with the twins' mother, Cynthia Huerta.

"It's not fair, it's not fair. He's free and I'm without my daughters," Huerta said in Spanish. "I can't find the words to describe this intense pain."

Friends described the twins as funny and full of dreams -- the types of kids who never hurt a soul. Lexi dreamed of being a veterinarian and Lexandra aspired to be a teacher.

"The [hit-and-run driver] hurt us very bad. I don't know what they were thinking," said the twins' aunt Magaly Huerta. "I don't know why they couldn't stop."

Over the weekend, so many people visited a makeshift memorial at the crash site that police had to set up a barricade to keep the crowds safe and away from traffic.

One person said she cannot believe someone could hit the girls and flee.

"It made me so sick to my stomach. To think three kids out to have fun could be killed like like that," said Martys Ownby.

The twins' family is asking the public to help with donations. They say they are unable to afford burial costs.