Aaron Thomas, right, is scheduled to take responsibility for a 2001 Leesburg rape. He backed out of an earlier plea deal in Prince William two weeks ago. (Tracy A. Woodward/The Washington Post)

More than 11 years after he bound a Leesburg woman with rope and viciously raped her in her apartment, Aaron Thomas sat shackled in a Loudoun County courtroom Thursday afternoon. He turned to his left, glanced at his defense attorney, then turned to the judge and softly said, “Guilty.”

Thomas, 41, for the first time took legal responsibility for being the East Coast Rapist, a man police say committed at least 13 attacks over two decades as he deftly dodged authorities and fooled everyone who knew him.

Thomas, linked to the attacks through DNA evidence, was convicted of one count of rape and one count of abduction. He is scheduled to enter similar pleas Friday in Prince William County.

Thursday’s pleas, entered in a mostly empty courtroom, marked the first stage of the end of the criminal cases against Thomas, who faces the possibility of two life sentences — and more, should he plead guilty again Friday. Other jurisdictions, including Fairfax and Prince George’s counties, also could pursue cases against him.

Police have linked Thomas to rapes and other attacks in Virginia, Maryland, Connecticut and Rhode Island. They also think he committed numerous rapes to which he hasn’t been connected.

A letter of apology handwritten by Aaron Thomas that he wrote on March 4, 2011, after he was interrogated by police.

Loudoun Commonwealth’s Attorney James E. Plowman said the pleas allowed the victim of the Leesburg attack — who sat behind Thomas in the courtroom — to avoid reliving her ordeal at trial. Plowman and the woman hugged after the hearing, which he said largely put to rest a case that has been open for more than a decade.

Each case in the string of attacks is an emotional one, Plowman said.

“Our incident here is horrific in and of itself,” he said after the hearing.

Thomas was quiet during the hearing. He cried through his words at times and used numerous tissues as he sat before Circuit Court Judge Thomas D. Horne.

At one point, Thomas blurted out: “I don’t know what’s going on here, and I don’t know what I’m doing,” recalling similar statements made two weeks ago in a failed plea hearing in Prince William, when he claimed that he didn’t understand the process. But Horne walked Thomas through the procedure and confirmed that the guilty pleas were, in fact, his own idea.

Thomas responded: “I’m hearing it’s what I’m supposed to do.”

In lengthy interviews with The Washington Post, Thomas said that he is the East Coast Rapist and that he had attacked women for half his life. Police said he confessed immediately after his capture in New Haven, Conn., in March 2011, following a years-long manhunt for a previously unknown assailant.

Explore the timeline

Thomas said Thursday that he was guilty of raping a woman who was moving out of her Leesburg apartment on May 24, 2001. The woman, then 41, said a man grabbed her from behind in the third-floor apartment on Plaza Street.

The woman reported that her attacker threatened her with a screwdriver, bound her and raped her on the floor of an unfurnished bedroom. He fled with her clothes and mobile phone.

“He did it just because he could,” the woman said in a 2010 interview with The Post. “It was like he had done it before, again and again.”

Thomas said in interviews that the Leesburg rape happened after he made a delivery in the area while working as a driver for an Alexandria lumber company. Thomas, then a Prince William resident, said he parked his truck and went walking through the neighborhood.

After his arrest, Thomas told detectives that he raped the Leesburg woman and wrote a letter of apology to her, according to court records released Thursday. In a letter dated March 4, 2011, Thomas wrote that he was “very sick” and had emotional problems and sexual urges that “I don’t have control of.”

“I’m just glad this is the end of my emtionnal sex problems,” he wrote, his block handwriting filled with spelling errors. “Sorry 4 hurting you emtionaley because I have problems with my self.”

The Prince William case, involving the abduction of three teenage trick-or-treaters on Halloween in 2009, is the most recent case in the lengthy string of attacks. In that case, Thomas allegedly used a fake gun to force the girls into the woods before he raped two of them.

Thomas has said he remembers few details of the attacks and does not remember his victims’ faces.

He also said he understands that he needs to be punished for the crimes but thinks there is something wrong with him that he doesn’t understand.