Donny Ray Williams Jr., a former Democratic congressional aide, pleaded guilty to sexually assaulting two women. His face was disfigured by an unrelated acid attack a year after his arrest. The protrusion on Williams’ head is the result of a rod surgically implanted to stretch the skin and promote healing. (Ricky Carioti/The Washington Post)

She sat in the back of the courtroom, wearing oversize black sunglasses, watching as the former Democratic congressional aide was sentenced for slipping a sedative into her drink and then raping her.

It was the summer of 2010, and she had just arrived in Washington as a student intern. When they met, she believed Donny Ray Williams Jr., the longtime aide and former staff director for a Senate Homeland Security and Governmental Affairs subcommittee, could help her find a job with Congress. But instead, she later told authorities, Williams drugged and assaulted her.

“He gave me a random dose of drugs and risked my life,” the woman wrote in a letter read during the D.C. Superior Court hearing last week. “After the assault, I moved away, and he continued to harass me and threatened me to drop the charges. This crime has caused me fear, pain and a financial burden.”

In the letter, the woman asked that Williams, who pleaded guilty to assaulting her and another woman and threatening a third person, be given “some jail time.” The other two people were not present in court.

Donny Ray Williams of the District poses for a photo in Washington. (Ricky Carioti/The Washington Post)

But as part of the plea deal, prosecutors agreed to ask the judge to suspend a 4 1/2-year prison term, meaning Williams will remain free as long as he stays out of trouble. Though the man before them had committed serious offenses, a prosecutor said, he had also suffered as a victim of an unrelated crime.

About a year after his arrest on the sex-assault charges, Williams was severely disfigured and badly injured after acid was thrown on his face. Authorities are still investigating the attack, and no arrests have been made.

During the hearing, Assistant U.S. Attorney Sharon Marcus-Kurn said Williams used his position to prey on his victims. “It was done with foresight, intentionally and deliberately,” Marcus-Kurn said. “The impact on these women is life-changing.”

But the prosecutor said the defendant’s life also was dramatically changed when he became a victim. She noted that Williams has had more than 20 surgeries, his vision is impaired and he faces additional “life-threatening” surgeries.

Judge Robert E. Morin said in court that he reluctantly agreed to suspend the prison term, noting he ultimately concluded the government’s reasoning was “practical and reasonable.”

“He was a victim of an independent crime and has serious medical issues,” Morin said. In addition to the suspended term, he sentenced Williams to five years of supervised probation and ordered him to register as a sex offender for 10 years and undergo counseling.

On July 3, 2013, Williams was walking down a Northwest Washington street when a man walked up and asked, “Hey, how are you man?” Williams, not recognizing the man, said “hey.”

The man then threw liquid in Williams’s face, and it ran down his body. Williams said he initially thought it was coffee. But then he felt pain as if his body were on fire. “I thought I was going to die,” he said in an interview earlier this year.

He suffered second- and third-degree burns and spent nearly two months in the hospital. He is blind in one eye, and his vision in the other is greatly diminished.

Williams said he thinks his attacker was the jealous ex-boyfriend of a woman he was dating.

Now, unemployed and living off his savings and help from his parents, he has amassed more than $1 million in medical bills. The political life he has aspired to live and has worked in since college is over.

It was a stunning fall for a young man who once had a promising future.

Williams was a member of the staff of the Senate Homeland Security and Government Affairs disaster recovery subcommittee from 2002 to 2007 and staff director for a subcommittee from April 2010 to July 2011. He began his Capitol Hill career in 1999 when he went to work for Rep. Elijah E. Cummings (D-Md.).

Williams said he grew up wanting to be a teacher, but while working for Cummings, he fell in love with politics.

He went on to work for panels chaired by former senators Joseph I. Lieberman (I-Conn.) and Mary Landrieu (D-La.). He also said he worked for former senator Herb Kohl (D-Wis.) and Rep. Jan Schakowsky (D-Ill.).

After the Sept. 11, 2001, terrorist attacks, Williams was tapped to work on the Homeland Security Act of 2002, which created the Homeland Security Department. In 2005, he worked on Landrieu’s committee in an effort to rebuild New Orleans after Hurricane Katrina.

In 2009, Williams spent a year in the White House working for the Obama administration as a congressional liaison for the U.S. Department of Housing and Urban Development.

“We were helping making changes in lives,” Williams said in the interview. “We were doing real work changing laws to help people immediately.”

In his earlier interview, Williams denied that he sexually assaulted the women, saying the relationships were consensual.

“I have slept with a lot of women. But I have never consciously thought about giving anybody a drug who didn’t know they were getting the drug,” Williams said then.

Instead, Williams said he decided to plead guilty because, since the attack, he wants to focus on his health, not a trial. And he wants to spend time with his 10-year-old son from his previous marriage.

But in court Friday, Williams sounded more remorseful. Standing before the judge, Williams apologized to his victims. He cited feminist author Bell Hooks, quoting from an essay she wrote on black male sexuality in American society. He quoted former senator Robert F. Kennedy speaking about using intimacy to build families.

Then he offered his own words.

“How easy it is for men to use power to abuse,” Williams said. “Rape is cowardly, shameful and downright evil. I promise, I will protect a woman’s right to her own body.”

The woman he assaulted, and her lawyer, declined to comment as they left court.