A judge in Virginia has accepted a guilty plea in what prosecutors say was an elaborate double-murder scheme involving a Brazilian au pair, an IRS agent, a pediatric nurse and a man who had been lured into their home with promises of rough sex. Juliana Peres Magalhães pleaded guilty to manslaughter in the killing of Joe Ryan in Fairfax County, Virginia. She said in court Tuesday that she and Brendan Banfield shot Ryan to frame him for the stabbing death of Christine Banfield. The au pair and the IRS agent then lived as a couple for months as detectives built the case. If she cooperates in Brendan Banfield's murder trial, she could be sentenced to time-served.