Prosecutors stepped up their scrutiny of Bernard Madoff's family and assets Tuesday, telling a judge they want to seize jewelry, business interests and more than $30 million that the disgraced money man and his wife lent to their two sons. The move was one of two motions that prosecutors filed Tuesday, four days after Madoff pleaded guilty to what could be the largest fraud in history. The other motion argued that Madoff must remain behind bars before his sentencing because his guilty plea creates a tremendous motive to flee, especially since he faces the near-certainty of a life prison sentence. Assistant US Attorney Lisa A. Baroni said strict bail conditions that have kept Madoff under guard in his apartment with an electronic ankle bracelet and video monitoring were not foolproof. She said Madoff "managed to perpetrate an enormous fraud, over the course of decades; his ingenuity should not be underestimated."