Justin Bieber before a concert in Mexico City last month. (Yuri Cortez/Getty Images)

Justin Bieber, the 17-year-old pop star, is in the midst of his first grown-up scandal: A 20-year-old California woman named Mariah Yeater has filed a suit claiming he fathered her 4-month-old son in a brief encounter at an L.A. concert. (**Update 11/16: Bieber paternity suit dropped. **) His denials have only fueled non-stop coverage of the case. So many questions!

• Can anyone accuse anyone of paternity?

No. “You have to prove some sort of access,” said California family law expert Steve Mindel. Yeater claims Bieber’s people plucked her from the audience and brought her backstage; on “Today” last week, the singer denied meeting her and said he always goes directly to his car after a show.

• Do a lot of stars get hit with claims like this?

Maybe — but we don’t hear about it usually. In California, establishing paternity is a confidential process, intended to protect the child and the parents. But RadarOnline somehow got a hold of this one last week. Mindel suspects that the unusually graphic court filings were leaked in hopes of cadging a settlement.

Mariah Yeater in a mugshot after a 2010 arrest in Las Vegas. (Handout/Las Vegas Metropolitan Police Department)

“Very,” said veteran publicist Ken Sunshine, who reps Leonardo DiCaprio, Barbra Streisand, Tyler Perry and others. “The number of attempts at shakedowns and trying to get money in the most outrageous and insane circumstances is a book in itself.”

There’s not a lot of public sympathy for celebrities — they get away with a lot, but they’re also constantly at risk of exaggerated and false claims. “You’re just a target when you’re famous,” he said.

• What’s the media’s role in this?

Huge. A 24-7 online news cycle, insane competition and bloggers unlikely to be be sued all contribute to the feverish rush to judgment. “Anyone can say anything and it becomes part of the news cycle,” said Sunshine.

• What’s next?

Bieber has agreed to take a paternity test after a European tour. And his team is threatening to “vigorously pursue” all legal options, including a defamation suit against Yeater — who may be facing charges of her own, even if Bieber turns out to be the dad. “She’s an adult and he’s a minor,” said Mindel. “No matter how you twist this Rubik’s Cube around, that’s statutory rape.”

Update: Justin Bieber paternity suit dropped, 11/16/11