ABC News' Matt Gutman and Benjamin Krolowitz report:

Karlie Tomica is a college student who'd crowned herself on Twitter as "Party Princess, Miami Beach."

Police say the 20-year-old took her title too literally, leaving the swanky Miami Beach club where she worked as a bartender with a blood alcohol content three times over the legal limit, and then speeding in her car into a well-known chef.

Emily Michot/AP Photo

The chef, 49-year-old Stefano Riccioletti, was walking to work when he was killed in the Jan. 28 accident, on Collins Avenue, one of Miami Beach's iconic strips. Riccioletti, who was married with three children, was the executive chef at Terraza at Shore Club, an upscale restaurant.

Police initially charged Tomica, 20, with leaving the scene of an accident, but added the DUI manslaughter charge Friday when they got the results of her blood alcohol test. She faces up to 30 years in prison if she's convicted.

Tomica was apparently leaving her bartending job at the popular Nikki Beach nightclub when she allegedly hit Riccioletti. He was reportedly thrown 30 feet by the impact. A witness called 911 and followed Tomica the 40 blocks to her Miami Beach condo, where police later arrested her.

Riccioletti's family members have filed lawsuits against Tomica and Nikki Beach, arguing the club is responsible for allowing Tomica to leave intoxicated.

Riccoletti's wife, Patrizia Pesce, said her first thought upon learning of her husband's death was her children. "How am I going to tell them that they have lost their Dad?" she recalled.

The family's attorney, Jose Baez, added: "Stefano is not here, and it doesn't matter if it is a car or a gun, he was killed. And the persons or person responsible for that need to be held accountable."

Tomica's attorney, Mark Shapiro, said his client is a young girl who made a tragic mistake. In court on Friday she wept openly, running towards her parents and mumbling "I have finals next week…"

"She's just a regular person who finds herself in this horrible situation," he said.