CONCORD, N.H. — A woman who New Hampshire prosecutors charged with lying to investigators about the disappearance of a University of New Hampshire sophomore last fall is expected to plead guilty.

Her lawyer says 19-year-old Kathryn McDonough of Portsmouth will plead guilty Thursday to hindering the prosecution, conspiracy and tampering with a witness. He said he expects her to be taken into custody at the conclusion of her court hearing.

McDonough’s ex-boyfriend — Seth Mazzaglia is charged with strangling 19-year-old Elizabeth “Lizzi” Marriott last October. The couple admitted to investigators that they dumped her body into the waters off Peirce Island in Portsmouth. It has never been recovered.

Marriott’s family members are expected to make statements during the hearing. Her father, Robert Marriott, did not return a phone call seeking comment.