Correction: An earlier version of this article incorrectly described the recommended prison sentence for Linwood Barnhill Jr. The proposed sentence, negotiated by the prosecution and Barnhill’s attorney, is seven years, not eight. This version has been corrected.

A former D.C. police officer admitted in federal court Friday that he forced underage teenagers to work as escorts out of his Southeast Washington apartment, but a judge expressed concern that the seven-year sentence negotiated by the prosecution and defense was too lenient.

Linwood Barnhill Jr., 48, who served on the force for 24 years and retired in advance of the hearing, pleaded guilty to two counts of pandering minors for prostitution and one count of possession of child pornography.

The deal reached by the U.S. attorney’s office and Barnhill’s attorney is lower than the nine to 12 years federal sentencing guidelines recommend for the officer. U.S. District Judge Rosemary M. Collyer said she would agree to the negotiated sentence only after she learns more about Barnhill’s background.

“I need to find out if the victims will have anything to say,” said Collyer, who set a Sept. 4 sentencing date. “This is not a victimless crime, and I have concerns about that.”

If Collyer does not accept the agreement, Barnhill can withdraw his deal and go to trial, work out a new deal with prosecutors or accept whatever sentence Collyer deems appropriate.

Barnhill admitted recruiting one girl at a mall and another at a bus stop, enticing them with promises of modeling jobs and Victoria’s Secret lingerie. He then set them up with men for $80 sex sessions. He said he kept $20.

On Friday, the towering Barnhill stood quietly before the judge and answered her questions using few words. He said he was pleading guilty “because I am guilty.” He will have to register as a sex offender, forfeit eight cellphones, a laptop and his black 2004 Lincoln Navigator to the government. He also agreed to give up his right to file a Freedom of Information Act request for the investigatory file to prevent him from learning names of victims and witnesses.

“Linwood Barnhill betrayed his duty to protect the community by trying to exploit teenage girls,” U.S. Attorney Ronald C. Machen Jr. said in a statement. “As a result of his deplorable conduct, he will now be headed to prison to join the criminals he spent his career locking up.”

D.C. Police Chief Cathy L. Lanier said in a statement that “a person of this character has no business being a police officer.”

The hearing brings the police department closer to ending a troubling chapter that began with a string of arrests of officers in November and December. Several of the accused, including Barnhill, worked out of the same District station in Southeast Washington. They were hired in 1989 and 1990, years when the department acknowledged that it lowered hiring standards to quickly add 1,500 members to the force during a particularly violent stretch in the city’s history.

Barnhill’s apartment was searched a day after officer Marc Washington was taken into custody. Police said Washington took lurid pictures of a runaway girl. Washington was found dead Dec. 10 in the Washington Channel, and his death has been ruled a suicide. Though both officers worked in Southeast’s 7th District station and were hired a year apart, authorities said there is no connection between the cases.

Police arrested Barnhill on Dec. 11 after parents traced a runaway 16-year-old girl to his apartment on Stanton Road. A 15-year-old girl was also inside the apartment. Police said they smelled burnt marijuana and found the drug in the officer’s bedroom. A police detective has previously testified in court that they found more than 100 condoms, “the number of condoms you would see in a brothel.”

The 16-year-old told police that she had met Barnhill at a mall and had been to Barnhill’s apartment several times. She said she was photographed in the nude. She also said she received a new hairstyle, shoes and clothes. She said Barnhill told her that her street name would be “Juicy.”

Court documents say the girl told police she had met six other young women or girls in the apartment and that several had been advertised on Backpage.com, an Internet bulletin board. Police who searched Barnhill’s apartment said they seized a mirror on which names of women whom the teenager said worked as prostitutes were written.

Wesley Robinson contributed to this report.