Federal prosecutors on Wednesday urged a New York judge to send two of the nation's most successful luxury real estate brokers and their brother to prison for life for drugging and raping dozens of women over a two-decade stretch, while defense lawyers recommended 15-year terms.

The lengthy written submissions by both sides precede the sentencing later this month of twins Oren and Alon Alexander, 39, and Tal Alexander, 40.

The brothers were convicted in March of multiple charges including sex trafficking, which carries a mandatory minimum penalty of 15 years in prison.