Federal prosecutors are seeking a 580-year prison sentence for a man who sexually abused six children, including two kidnapped Amish girls in northern New York.

Stephen M. Howells, 40, and Nicole F. Vaisey, 26, admitted in May that they sexually exploited the children. The abuse ended after the couple was arrested for briefly kidnapping two young Amish girls at a farm stand in northern New York in August 2014.

They will be sentenced Dec. 17 in federal court in Syracuse.

Prosecutors asking for the maximum sentence against Howells in a court filing this week said the girls were "subjected to degrading and unspeakable brutalities."

Howell's public defender asked for a 30-year sentence, saying he was remorseful and accepts responsibility.

Prosecutors hadn't filed a recommended sentence for Vaisey by Friday.