The school in Northeast Washington where police and education authorities say a teacher and a student had a sexual encounter in October 2014. (Marlon Correa/The Washington Post)

Prosecutors dropped a first-degree sexual-abuse charge against a 22-year-old substitute teacher who was arrested in October and charged with having oral sex with a student football player at a D.C. charter school.

At a hearing Thursday in D.C. Superior Court, Symone Greene pleaded guilty to one felony count of obstruction of justice in connection with having sexual contact with the 17-year-old student at Options Public Charter School in Northeast Washington and then urging the teen not to cooperate with authorities.

In addition to dropping the charge of sex abuse of a minor, prosecutors agreed to a three-year, suspended prison sentence. Greene also would be prohibited from having supervisory responsibility for minors.

The plea deal is pending before Judge Rhonda Reid-Winston. Should the judge accept the agreement, Greene will be sentenced in October. Prosecutors and Greene’s attorney, Heather Pinckney, spent months in negotiations about the case.

A spokesman for the U.S. attorney declined to elaborate on the reason that prosecutors dropped the sexual-assault charge. “The U.S. attorney’s office extended the plea offer after a thorough investigation of the facts, circumstances and evidence in the case,” spokesman William Miller said.

After the hearing, Pinckney declined to comment.

According to police and court documents, Greene performed the sex act behind her classroom desk after an English class while other students attended a pep rally. The teen secretly recorded part of the encounter on video. Police said the student showed the video to five of his football teammates and a childhood friend. School leaders believe the video spread rapidly within the school community. A faculty member saw the video and reported it to senior staff members, who notified city officials.

The student and teacher texted each other throughout the weekend after the sexual encounter, and the teacher sent him a clothed picture of herself while urging him to “chill” because she could get in trouble for what had happened, police said.

Authorities said the two met for the first time that day but flirted throughout the first class. Near the end of the final class, the student gave the teacher his cellphone number.

Greene, who lives in Fort Washington with her parents, has been on high-intensity supervision and was wearing an electronic ankle bracelet.

After the arrest, the parents of the teenager filed an $11 million lawsuit against the teacher, the D.C. Public Charter School Board and the private firm that hired Greene to work at the school for at-risk students.