ABC News' Taylor Behrendt reports:

A scary run-in at a Los Angeles gym left actress Mila Kunis hiding in her Range Rover from a homeless man accused of stalking her.

Los Angeles police say the man, 27-year-old Stuart Dunn, showed up at Kunis' gym on Friday, the third straight day he followed the "Black Swan" star to the gym in hopes of meeting her.

The actress, 28, reportedly hid in her Range Rover until Los Angeles police arrived and swarmed the location with squad cars, DailyFill.com reported.

"Stuart Dunn was detained at a local gym in Los Angeles …he was detained apparently for stalking Ms. Kunis," Los Angeles Police Officer Cleon Joseph said.

Dunn, a homeless man described as 5-feet-7 and 125 pounds, was no stranger to Kunis.  He was arrested in January by the Los Angeles County Sheriff for attempting to break in to her California home.

Dunn pleaded no contest to unauthorized entry of a private dwelling and was sentenced in February to three years probation and 60 days in jail, according to the Los Angeles County District Attorney's office.

"He was caught, charged and plead no contest for entering the house and placed on probation and it did not stop," said Harvey Levin of TMZ.  "It is just a scary situation."

Kunis  had reportedly beefed up her security since the attempted break-in.

Dunn isn't the first fan to become infatuated with Kunis.

Last year Christopher Chaney, 36, hacked into Kunis' email account and stole private information and photos.  He pleaded guilty in March.

"Celebrities are just like anyone else," Rhonda Saunders, a Los Angeles County assistant district attorney who is a specialist in stalking cases, told ABC News.  "When they're being stalked they're very fearful.  They're afraid for themselves.  They're afraid for their families. They're afraid for the people around them."

Dunn is currently being held at a mental facility for evaluation.  He could go to jail if authorities determine he violated the judge's three-year probation.