By Zachary Cohen, Curt Devine, Drew Griffin and Michael Warren, CNN

(CNN) -- President Donald Trump said Tuesday that acting Defense Secretary Patrick Shanahan has "decided not to go forward with his confirmation process." Shanahan's withdrawal was announced shortly after the Washington Post published a report detailing a violent incident in 2011 in which his son attacked his own mother with a baseball bat.

"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.

"I thank Pat for his outstanding service and will be naming Secretary of the Army, Mark Esper, to be the new Acting Secretary of Defense. I know Mark, and have no doubt he will do a fantastic job!" he added.

Trump announced his intention to nominate Shanahan on May 9, but the paperwork necessary to begin confirmation hearings hadn't been filed.

On Tuesday, the Washington Post reported details related to a November 2011 incident in which Shanahan rushed to defend his then-17-year-old son, William, in the days after the teenager brutally beat his mother with a baseball bat.

Two weeks later, Shanahan wrote a memo to prepare his son's initial court appearance, arguing that he had acted in self defense, according to the Post.

But in an interview on Monday, Shanahan told the Post that he later regretted writing the memo and never intended for anyone other than his son's attorneys to read it.

"Quite frankly it's difficult to relive that moment and the passage was difficult for me to read. I was wrong to write those three sentences," Shanahan told the Post.

"I have never believed Will's attack on his mother was an act of self-defense or justified. I don't believe violence is appropriate ever, and certainly never any justification for attacking someone with a baseball bat," he said.

Later Tuesday, Shanahan released a statement saying he withdrew from consideration after details surfaced related to "a painful and deeply personal family situation from long ago."

"After having been confirmed for Deputy Secretary less than two years ago, it is unfortunate that a painful and deeply personal family situation from long ago is being dredged up and painted in an incomplete and therefore misleading way in the course of this process," he said.

"I believe my continuing in the confirmation process would force my three children to relive a traumatic chapter in our family's life and reopen wounds we have worked years to heal. Ultimately, their safety and well-being is my highest priority," Shanahan added.

An administration official told CNN on Tuesday that it was Shanahan's decision to resign as acting secretary of defense and that the White House did not ask or pressure him for his resignation.

The source contends that Shanahan was fully vetted and that the White House was aware of the domestic abuse allegations in his family -- though not every single detail.

The view early on was that it was not him personally. But as previously reported, even though he was never arrested or charged, there had been growing concerns in recent days his ex-wife would resurface and publicly accuse him of domestic abuse which would then cause parallels to be drawn about the situation involving former White House aide Rob Porter.

Court filings detail 2010 incident

In court filings, Shanahan's ex-wife Kimberley accused him of hitting her during a dispute at their home in August 2010.

A police officer who responded to the dispute noted that "Patrick had a black eye and a bloody nose" and that Kimberley did not have "any visible marks" on her, though Kimberley told the officer Patrick struck her several times in the stomach, according to a police incident report.

His ex-wife, who later changed her name to Kimberly Jordinson, was arrested and charged with assault for the incident. The charges against her were later dropped.

In an unrelated incident, Jordinson was also arrested in Florida in 2014, for smashing a car's front and back windshields with a sledgehammer according to a police report, but she was not convicted.

When CNN spoke to Jordinson in January, she said she stood by her allegations. She also said she had not spoken to Shanahan since the 2010 incident, and that the two only communicated through attorneys.

Shanahan addressed the issue in a statement earlier this week.

"Though my marriage ended in sorrow and disappointment, I never laid a hand on my then-wife and cooperated fully in a thorough law enforcement investigation that resulted in her being charged with assault against me—charges which I had dropped in the interest of my family," he said.

Patrick and Kimberley's daughter Kayla Shanahan released her own statement saying: "I never once saw my father raise a hand against my mother or against his children. To the contrary, my mother has a history of domestic abuse and physical violence, victimizing my father and her children, as well as having been subject of a restraining order unrelated to our family."

Their son, Will Shanahan defended his father as a "source of stability."

"I and my brother and sister were subject to emotional and physical abuse by our mother. My father was and is the source of stability in our lives, in contrast to the constant physical and emotional trauma inflicted on us by our mother," he said in a statement.

Trump taps Esper as acting secretary

Esper, who Trump named as acting defense secretary on Tuesday, has been floated within the administration as a potential Pentagon chief for months — both before and after Trump said he would nominate Shanahan to the post.

Now, as Shanahan withdraws, the President is again considering the former Army secretary for the permanent job — though has only named him to the acting post for now. One White House official said the administration is still regrouping and figuring out their next steps after Shanahan's withdrawal.

Esper was Trump's third pick for army secretary, and has been involved in efforts to secure funding for the border wall and to deploy US troops to the southern border.

Esper received a call from the White House about 30 minutes before the tweet announcing him as acting secretary, according to a US defense official.

The service secretaries, including Esper, will meet later Tuesday afternoon with Shanahan to discuss a transition.

"This is a good move by the administration," a senior GOP aide on the Senate Armed Services Committee said, predicting a smooth confirmation should the White House name Esper to the permanent post.

"They don't make him acting without nominating him," the aide said. "Esper would be a very smart pick for the White House."

Trump was generally aware for months of the rumors about Shanahan and domestic violence allegations, though it's not clear to what extent he knew the details.

The White House had grown increasingly concerned in recent days over Shanahan's issues with his background check, a White House official said. Additionally, Trump began having second thoughts about nominating him after initially telling Shanahan in the Oval Office he would, according to the official.

The official added that Shanahan stylistically didn't fit Trump's mold of what he wanted in a defensesSecretary and he began to question whether that was the right role for him. Shanahan is more reserved and is not an aggressive and forward type of leader. He also doesn't have military experience.

"The defense secretary plays a leadership role, not a business management role. Huge difference," the official said.

Asked about Esper's interest in the secretary of defense role, his spokesman pointed to a December statement in which the Army secretary told the Ft. Worth Star-Telegram: "I'm very happy and privileged to be secretary of the Army."

A senior GOP aide on the Senate Armed Services Committee told CNN Tuesday that naming Esper to replace Shanahan was "a good move by the administration" and said he would be "a very smart pick" should the White House choose to nominate him.

"He would have a very smooth confirmation," the aide said, adding that Esper is "the most qualified in the Department."

The aide also told CNN that most committee staff are relieved about Trump's announcement.

"We don't have to go through that confirmation battle," they said, referring to Shanahan.

An administration official said Esper is "potentially qualified" for the permanent job but that several other people are also being considered.

The source added that the White House wants someone as quickly as possible, but that it is just starting the replacement process.