DOYLESTOWN, Pa. — A jailed man who has been the focus of an investigation into the disappearances of four men admitted on Thursday that he killed them and agreed to plead guilty to four murder counts, his attorney said in a surprise development.

Cosmo DiNardo, 20, confessed to the commission or participation in four murders, attorney Paul Lang said outside court, where DiNardo had met with investigators. DiNardo also told investigators where the bodies are.

“I’m sorry,” a shackled DiNardo said as he left the courthouse.

In exchange for the cooperation, Lang said, prosecutors were taking the death penalty off the table. There was no immediate comment from prosecutors.