TMZ has obtained the mug shot for the woman who claims she's Justin Bieber's baby mama ... taken moments after she was arrested for allegedly slapping her ex-BF last year ... the OTHER guy she accused of fathering her child.
As we previously reported, Mariah Yeater was charged with battery in December 2010 for slapping her ex-BF John Terranova ... after she told the guy he was the father of her then-unborn baby.
John claims the baby isn't his -- ditto for Bieber.
Yeater is due back in a Vegas courtroom in the near future.
Bieber's Alleged Baby Mama
THE MUG SHOT
11/4/2011 4:23 PM PDT BY TMZ STAFF
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