She entered the plea Wednesday through her attorney.
Superior Court Judge Keith Schwartz set bail at $40,000. He says it appears Lohan violated her probation and told her not to push her luck by getting into any more trouble.
The “Mean Girls” star was met by a swarm of photographers when she arrived at the Airport Courthouse near Los Angeles International Airport for her arraignment in a white dress and sunglasses.
Prosecutors claim the 24-year-old starlet took the necklace in January while on probation for a 2007 drunken driving case.
If convicted of the theft charge, Lohan could face up to three years in state prison.
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