DOVER, N.H. – A man serving a life sentence for the rape and slaying of a University of New Hampshire student has pleaded guilty to attempted escape from jail and was sentenced to an additional 3½ to seven years in prison.

Seth Mazzaglia was charged with plotting to escape from the Strafford County House of Correction while awaiting trial on rape and murder charges. He faced trial but pleaded guilty Friday, instead.

A former cellmate testified Mazzaglia asked him to obtain a gun, two cars and disguises to use in the jailbreak.

The 32-year-old Mazzaglia was convicted June 27 and is serving a sentence of life without parole for the 2012 death of 19-year-old Elizabeth “Lizzi” Marriott of Westborough, Massachusetts.

Prosecutors say he choked Marriott after she rebuffed his sexual advances.