A Times Square karaoke club worker has pleaded guilty to beating a patron to death with a steel pipe and slashing her throat on the roof while the club threw a party honoring Lil' Kim's birthday.

Syed Rahman, 25, expects a sentence of 20 years to life after pleading guilty Tuesday in a Manhattan courthouse to murdering 24-year-old Ingrid Rivera. It wasn't clear whether Lil' Kim was at the August 2008 party at Spotlight Live. A spokesperson for the rapper did not immediately respond to an e-mail message.

Rahman's lawyer, Peter Frankel, said his client and Rivera were strangers before they met at the club. Frankel declined to describe what happened but said it was "a series of horrible events" fueled in part by Rahman's drinking and drug use.