Bling Ring Ringleader Nick Prugo Sentenced to JAIL ... Again

Nick Prugo -- who masterminded the Bling Ring string of heists on L.A. celebs -- has just been sentenced to 160 days in jail for violating his parole.

TMZ broke the story ... Nick got dragged into a murder-for-hire case involving the skin care specialist to the stars, who allegedly solicited a former Detroit Lions' player to kill one of her competitors.

When the skin care lady was arrested, she dropped a dime on Nick, telling cops she was friends with him and he had left California in violation of his parole.

Nick served prison time for his role in the Bling Ring cases.

In the current case ... the judge mentioned that Nick may have also committed credit card fraud.