Ivan Mejia, spokesman for the Security Ministry, confirmed that a suspect had surrendered, but offered no further details.
University president Julieta Castellanos told The Associated Press that she hired a private investigator to find the suspect, Santos Padilla. She said she gave the information to authorities, and the officer surrendered to Honduras' human rights commission after police started looking for him.
Castellanos' son was slain with a friend a year ago and their killings sparked a movement against police corruption and impunity.
The motive in the crime remains a mystery, but prosecutors say four police officers kidnapped and killed the two young men. Another officer already is in custody, and two remain at large.
Castellanos announced Padilla's surrender as she was addressing President Porfirio Lobo and academics on behalf of the Commission on Public Safety Reform created in January to crack down on crooked cops.
"We personally tracked the suspect down and found out his location. We cross-checked our information with the police because they have the power to arrest him, and when he felt cornered he decided to turn himself in," she later told the AP.
Although prosecutors have said four officers were involved, Padilla is suspected of being the killer, Castellanos said.
"The information we have is Padilla was the one who pulled the trigger and fired the shots that killed my son and his friend," she said.
Castellanos has led a crusade to overhaul the National Police and fire officers involved in drug trafficking, murder and kidnapping in this country of 8 million people. Because of her son's murder, the then police chief and his deputy were fired and authorities began purging officers accused of crimes.
The new head of the National Police says he is seeing internal discontent over the suspensions of high-ranking officers as part of the effort to root out corruption.
Those angered at the chief say he is really just removing personal rivals. Chief Juan Carlos Bonilla himself was acquitted in 2004 on a murder charge after he was accused of running a death squad when he was a regional police head.