Kathryn McDonough of Portsmouth pleaded guilty to hindering prosecution, conspiracy and tampering. McDonough's ex-boyfriend - Seth Mazzaglia is charged with strangling 19-year-old Lizzi Marriott last... more 
Kathryn McDonough of Portsmouth pleaded guilty to hindering prosecution, conspiracy and tampering. McDonough's ex-boyfriend - Seth Mazzaglia is charged with strangling 19-year-old Lizzi Marriott last October. less 
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WCVB - Boston
Fri, Jul 26, 2013 7:15 AM EDT