Who is Judge Maryellen Noreika, the district court judge for Hunter Biden's plea deal?

The real-time dissolution of a tentative plea deal between Hunter Biden and federal prosecutors in a Delaware courtroom Wednesday focused attention on Maryellen Noreika, the federal district court judge overseeing the case. 

Although plea deals must be approved by a judge, it's rare that they fall apart in live court, particularly in such a high-profile case. Hunter Biden's tentative agreement would have entailed pleading guilty to two counts of evading taxes and a diversion agreement requiring him to remain drug-free and crime-free to see a felony gun charge dismissed. 

But Noreika questioned whether it meant the president's son would be immune from prosecution for any other potential crimes, and expressed her discomfort with terms of the deal when an investigation was ongoing.