The former R&B crooner, whose real name is Robert Kelly, could spend the rest of his life in prison. Federal prosecutors say he deserves to be sentenced in "excess of 25 years" due to the severe nature of his offenses.

In September, during his sex-trafficking trial, a jury found Kelly, 55, guilty on nine counts, including leading a criminal enterprise that recruited women and children for sex, which prosecutors called "calculated" and "methodical."

During his trial, nearly four dozen witnesses testified for the prosecution, alleging that he preyed upon children and women for his sexual gratification.

He was also convicted in a bribery scheme involving a public official to get a fake ID for the late singer Aaliyah, so the two could marry when she was 15 and he was 27. Kelly believed Aaliyah was pregnant at the time, prosecutors wrote in a sentencing memo.

Kelly produced Aaliyah's debut album, titled "Age Ain't Nothing but a Number." She died in a plane crash in 2001 at 22 years old.

"Kelly relied upon his fame, money and popularity as an R&B recording star and used the large network of people his status afforded him -- including his business managers, security guards and bouncers, runners, lawyers, accountants and assistants to both carry out and conceal his crimes," prosecutors said.

"He continued his crimes and avoided punishment for them for almost 30 years and must now be held to account."