On Tuesday, amid a worsening political crisis with Iran, President Donald Trump abruptly announced a shake-up atop the U.S. Armed Forces. “Acting Secretary of Defense Patrick Shanahan, who has done a wonderful job, has decided not to go forward with his confirmation process so that he can devote more time to his family,” Trump tweeted, explaining that he is nominating Mark Esper, the current secretary of the Army, to lead the Pentagon instead. “I know Mark, and have no doubt he will do a fantastic job!”

While it’s not the first time a Trump Cabinet shuffle has resembled a game of musical chairs, the nature of Shanahan’s departure—and Esper’s nomination—is murkier than usual. Shortly before the president’s announcement, USA Today reported that the FBI has been investigating a violent domestic dispute between Shanahan and his ex-wife that took place in 2010. (The FBI declined the outlet’s request for comment.) Minutes after Trump nominated Esper, the Washington Post published an article in which Shanahan confirmed a series of violent incidents involving his family, including one in which he was physically assaulted by his then-wife, and another in which she was attacked by their son. “Bad things can happen to good families…and this is a tragedy, really,” Shanahan said. Addressing the episode publicly, he said, “will ruin my son’s life.” Shanahan was also concerned that his history would be “a distraction” for the Department of Defense and for Trump himself, Axios reported Tuesday. In a meeting Tuesday morning, attended by Trump, Chief of Staff Mick Mulvaney, White House counsel Pat Cipollone, and National Security Adviser John Bolton, among others, Shanahan reportedly asked to withdraw his nomination, to which Trump replied he would “support him either way.”

Shanahan, who succeeded James Mattis but was never formally confirmed in the role, was already facing opposition for his lack of foreign-policy experience and his past career at Boeing. The events described by USA Today, however, appear to have made his position untenable. According to the paper, the FBI was in the middle of investigating an incident between Shanahan and his then-wife, Kimberley Jordinson, in which an argument ended in physical violence. In a police report, each claimed the other was the aggressor. Jordinson was eventually charged with domestic assault, though the charges were dropped due to a lack of evidence. (In a statement, Shanahan said he “never laid a hand on my then-wife and cooperated fully in a thorough law enforcement investigation,” adding that he wished “nothing but the best for her.”)

Perhaps intending to get out ahead of the story, Shanahan spoke to the Post on Monday and Tuesday about another violent episode in his family’s history: In 2011, his son William Shanahan beat his mother with a baseball bat, leaving her “unconscious in a pool of blood, her skull fractured and with internal injuries that required surgery,” per court and police records. Shanahan reportedly worked to keep Will out of jail, drafting a memo suggesting that Will had acted in self-defense. “Use of a baseball bat in self-defense will likely be viewed as an imbalance of force,” Shanahan wrote. “However, Will’s mother harassed him for nearly three hours before the incident.”

Shanahan told the Post that as the case went on, he came to realize he had been mistaken. “Quite frankly it’s difficult to relive that moment and the passage was difficult for me to read. I was wrong to write those…sentences,” he said. William was sentenced to 18 months at a juvenile facility and four years of probation, which were eventually reduced. He enrolled at the University of Washington, where Shanahan sat on the board of regents, and graduated with a political science degree.