The steps that led to that arrest began when he and his brother, Andrew, confronted their father over his plans to distribute hundreds of millions of dollars in bonuses to employees months ahead of schedule.
According to documents filed by the F.B.I. at the time of the arrest, that meeting led to a private conversation on Dec. 10, 2008, in which Bernard Madoff told his sons that their entire lives — all the wealth and success the family seemed to possess — were based on a lie. His apparently lucrative money-management business was nothing but an immense Ponzi scheme, and it was crumbling under the relentless pressures of the financial crisis of late 2008.
Mark and his brother immediately consulted a lawyer and were advised they had to report their father’s confession to law enforcement. They did so, and the following morning their father was arrested at his Manhattan penthouse.
The public fury over the stunning crime — Bernard Madoff estimated the losses at $50 billion — was not limited to its mastermind. Mark Madoff, his mother and his brother were all the subject of constant media speculation. Some blogs repeatedly predicted their imminent arrest, and many articles speculated that they had been involved in their father’s crime, or at least were aware of it.
But charges have not been filed against any of the immediate family members, and their lawyer has said publicly that neither Mark Madoff nor his brother has ever been notified by prosecutors that they were the subjects of a criminal investigation.
A person close to Mark Madoff said he had been increasingly distraught as the anniversary of his father’s arrest approached, and he had been upset at some recent news coverage speculating that criminal charges against him and his brother were still likely.
Gregarious and handsome, Mark was the more outgoing of Mr. Madoff’s two sons. At the University of Michigan, his social circle included students largely from other well-to-do East Coast families. He was a member of the Sigma Alpha Mu, a Jewish fraternity.He graduated in 1986 and moved to New York to join his father’s firm. Where most of his friends rented crammed studios, Mark lived in an apartment his father had bought for him in Sterling Plaza, a luxury high-rise on Manhattan’s east side developed by Sterling Equities. Sterling is controlled by Fred Wilpon, the owner of the New York Mets and a close friend of Mr. Madoff whose businesses had invested hundreds of millions of dollars in the Ponzi scheme.
Mark Madoff married his college sweetheart, Susan, and moved to Greenwich, Conn., where they raised two children. They divorced in the 1990s and Mark eventually moved back to Manhattan. He was remarried, to Stephanie Mikesell, and had two more children with her.
Peter Lattman, Liz Robbins and Tim Stelloh contributed reporting.