Last year, they sued Andrew Young, a King confidante who helped their father coordinate civil rights efforts throughout the South, over footage of King that shows up in a series produced by Young's foundation. The King children acted in 2008 to block actor and singer Harry Belafonte from auctioning documents that their parents had given Belafonte years earlier, leading Belafonte to sue the younger Kings last year in hopes of determining legal ownership.
Young has said the Kings' lawsuit doesn't bother him because the question of rightful ownership does need to be sorted out, especially because certain aspects of King's legacy belong to him, too. Lawyers on both sides of the Belafonte lawsuit did not return telephone calls seeking comment; court papers indicate a settlement is being pursued.
The King heirs even have used the courts to fight each other.
In 2008, Bernice and Martin III sued Dexter, accusing him of acting improperly as head of their father's estate. The three reached a private settlement in October 2009.
Now they're back in court again, with Martin III and Dexter suing Bernice over her possession of their father's Bible and his 1964 Nobel Peace Prize medal.
Both items are likely to gain value: The 50th anniversary of King's Nobel Prize is later this year, and King's personal Bible was used to swear in President Barack Obama during his second inauguration in 2013.
Bernice King refused to turn them over, saying her brothers want to sell them, just as the three of them have sold other items that belonged to their father.
"I take this strong position for my father because Daddy is not here to say himself, 'My Bible and my medals are never to be sold not to an institution or even a person,'" she said during a news conference this month at Atlanta's Ebenezer Baptist Church. Her brothers, who run King's estate, have not responded publicly to their sister's complaints.