A woman mowed down dozens of pedestrians on the Las Vegas Strip, killing one, before asking a valet to call the police.
People jumped on the car and banged on its windows, but Lakeisha N. Holloway, 24, would not stop driving on the sidewalk, Sheriff Joe Lombardo told reporters.
Video appeared to show the crash in front of the Paris and Planet Hollywood casino-hotels was intentional, he said.
The 1996 Oldsmobile sedan was fully on the sidewalk twice Sunday night, including once when it traveled for 60 metres, police said.
The child in the car was not hurt.
Authorities have identified the person who died as Jessica Valenzuela, 32, of Buckeye, Arizona.
The crash happened on a busy stretch of Las Vegas Boulevard across from the dancing water fountains of the Bellagio hotel-casino where visitors crowd sidewalks as they head from one casino to another.
The Miss Universe pageant was being held nearby at Planet Hollywood.
Holloway drove a few blocks to a hotel, parked and asked a valet to call police, saying she had run over some people on the Strip, Lombardo said.
She was stoic when she was arrested, he said.
Lombardo said police did not have a definitive motive but that they believe she had a falling out with the father of her child before the crash.
A drug recognition expert on the scene determined Holloway was under the influence of a ``stimulant," but blood test results were pending.
Holloway last lived in Oregon and had been in Las Vegas for about a week, where she was believed to be homeless and living in the car, authorities said.
She faces a charge of murder with a deadly weapon and is being held without bail, prosecutors say.
District Attorney Steve Wolfson said he also is considering a slew of other charges.
At least 35 people injured in the crash were taken to hospitals, including three people still in critical condition with head injuries, officials said
Victims hailed from Oregon, Florida, Colorado, California, Washington, Mexico, and Quebec, Canada. Five were Canadian citizens and four were Oregon college students in town to compete in a wrestling tournament.
Justin Cochrane, a visitor from Santa Barbara, California, said he was having dinner at a sidewalk restaurant outside the Paris hotel when he saw the car smashing into pedestrians.
``It was just massacring people," he said, adding that the car appeared to be going around 65kmh.
The Oldsmobile then went down the road and drove back into another crowd of pedestrians on the sidewalk, he said.
Cochrane said he couldn't understand why the car went into the crowd a second time.
"Why would it slow to go around and then accelerate again?" he said. "I thought, `It's a crazy person."