The 19-year-old woman accused of killing her newborn son and leaving him in a motel trash bin reportedly will join her former beau in pleading guilty to manslaughter.

Amy Grossberg and her attorneys decided on a plea deal after learning what former boyfriend Brian Peterson would say in testimony against her, The (Wilmington) News-Journal reported Tuesday. The report gave no details of what Peterson had allegedly said, but quoted one source as saying it was "devastating" to Grossberg's defense.