A bar employee at a popular New York karaoke club was taken into custody on Thursday after admitting to having beaten a woman to death with a metal pipe on the roof of the nightclub, while a party was being held inside, police said.

Syed Rahman, aged 24, confessed he struck Ingrid Rivera of Queens on the back of the head at about 2.45 a.m. on Monday, during rapper Lil’ Kim’s birthday party that the victim had paid to be present at, Police Commissioner Raymond Kelly said at a news conference, cited by The Associated Press. The woman’s body was found on Wednesday afternoon.

A friend of Ingrid Rivera told authorities that she had rejected the club worker’s sexual advances shortly before her friend was murdered, Mr. Kelly said, according to the same source.

Syed Rahman had been working at the club for approximately four years and had no previous criminal record. However, the attacker was arrested on a charge of second-degree murder and risks a penalty up to life imprisonment.

An autopsy conducted on the victim’s body found that the 24-year-old woman died from a blow to the head. Thus, on Thursday, the medical examiner ruled Ingrid Rivera’s death a homicide, The Associated Press reported.

Rivera was a Lil’ Kim fan who attended the event with the intention of offering her idol a flower bouquet, according to police statements. However, she was forced to leave the club because she had accidentally entered the men’s rest room. Police said Rahman lured the victim to the roof by telling her he could get her back inside.

Rahman was found on Wednesday at an upper Manhattan apartment where he lives with his parents, according to the AP.