(Dover, NH) - 20 year old Katheryn "Kat" McDonough will spend another day on the witness stand in the Seth Mazzaglia murder trial in Strafford County Superior Court in Dover.The states star witness faces a third day of cross examination by defense attorneys. McDonough had testified last week that she saw her boyfriend, Seth Mazzaglia,  strangle Elizabeth Marriott to death in his Dover apartment in October of 2012. She admitted that she and Mazzaglia then dumped the body in the Piscataqua River in Portsmouth. The body has never been recovered. The defense contends that Marriott died during a consentual sex act with McDonough and that she had admitted that to investigators, but changed her story after being offered a plea deal that included immunity.

Kat McDonough (PD Photo)