Army Brig. Gen. Jeffrey Sinclair was fined $20,000 and reprimanded but avoided jail time Thursday after he acknowledged committing adultery and mistreating his former mistress, an Army captain.

The former deputy commander of the 82nd Airborne Division originally had faced sexual assault charges involving the junior officer. But the case against him fell apart after the trial judge ruled that the decision to seek trial might have been influenced by political considerations.

Sinclair was prosecuted at a time when the military is under pressure from Congress and victim advocates for not doing enough to stem a rise in sexual abuse within the ranks.

The Army prosecution did not seek jail time for Sinclair, although the crimes he admitted technically carried a potential prison term.

He was sentenced after pleading guilty to lesser counts that included improper relationships with three women, possession of pornography while deployed to Afghanistan and mistreatment of a female captain who had been his mistress for three years. Other allegations he admitted involved use of profanity and misusing a government credit card.

The defense argued against jail time for actions that would not be criminal acts outside the Army.

The female captain testified during the sentencing proceedings Tuesday that her life has changed because of Sinclair. "I'm very guarded now. I have a hard time trusting people. I have a very hard time feeling safe," she said.

Sinclair's wife, Rebecca, has not attended the proceedings. But she wrote a letter asking that the judge not punish her or the couple's two sons by taking away his military pension and other benefits.

"He is wracked with guilt over the pain he has caused me, my children and the Army," she wrote.

Before sentencing, Army prosecutors agreed Monday to drop the more serious charges that Sinclair sexually assaulted his mistress on several occasions between 2010 and 2012, including while both were in Afghanistan.

Sinclair, 51, is one of the highest-ranking military officers to face allegations of sexual assault.

He had offered to plead guilty to lesser charges as far back as December, insisting that he was innocent of sexual assault and that physical contact with the captain had been consensual. But Lt. Gen. Joseph Anderson, the commanding general at Fort Bragg at that time, rejected the plea offer after receiving a letter from an advocate for the accuser urging Anderson to send the case to trial.

Capt. Cassie Fowler, the advocate appointed by the Army, had warned Anderson that if he accepted Sinclair's plea to lesser charges, he would embolden political efforts underway in Washington to remove these types of decisions about sexual assault prosecution from the military chain of command.

A law seeking just such a change had been introduced by Sen. Kirsten Gillibrand, D-N.Y., It was rejected by the Senate earlier this month.

Fowler also wrote to Anderson that failure to bring Sinclair to trial would "send the wrong signal to those senior commanders who would prey on their subordinates."

The prosecution case unraveled early last week — just as cross-examination of the accuser was about to begin — when prosecutors, in response to a defense discovery request, made available Fowler's letter to Anderson.

The defense immediately brought a motion asserting that Anderson's decision to reject the early plea bargain offer was politically motivated because of that letter. Anderson, currently deployed to Afghanistan, denied this in telephone testimony.

But Col. James Pohl, the trial judge, found there might have been undue influence in Anderson's decision. Pohl suspended trial proceedings and allowed Sinclair to re-open plea negotiations with another commanding officer, Maj. Gen. Clarence Chinn.

Chinn approved a plea agreement to the remaining lesser charges over the weekend. Under that agreement, the prosecution dropped the more serious, sexual assault allegations.

A war of words later erupted between opposite sides in the case.

Sinclair's lawyer, Richard Scheff, said the Army had wasted "millions of taxpayer dollars" bringing his client to trial.

A lawyer and retired Navy rear admiral Jamie Barnett, who was advising the victim in the case, issued a statement on her behalf Monday, saying that she stands by her allegations of sexual assault.

"The Army and the military in general must learn that when a superior officer has authority over someone towards whom he is making improper advances, it is not a consensual affair. It is abuse and a victimization of a junior person," Barnett said.