Former Philadelphia police inspector Daniel Castro is expected to plead guilty in federal court Thursday to one of the charges he is facing.

Castro, 47, was indicted in the winter on accusations that he plotted an extortion scheme to shake down a former business partner who owed him money. A jury deadlocked on most of those charges in April, but last month, federal prosecutors announced plans to retry Castro this summer.

Documents filed in the U.S. Attorney's Office indicate that the 25-year veteran of the department, who once aspired to become commissioner, will change a plea Thursday, but it was not clear to which charge he will plead guilty.

The U.S. Attorney's Office and Castro's lawyer, Brian McMonagle, declined to comment Wednesday.

Sources familiar with the case have speculated that Castro could plead guilty to one count of the indictment if prosecutors agreed to dismiss other counts.

During his trial, Castro admitted planning the extortion, but argued that the government had entrapped him by directing an informant to talk him into it.

During his testimony, Castro struck an emotional and sometimes angry tone. He wept several times while describing his downfall, and described himself as a man desperate to recoup his $90,000.

The jury was deadlocked on eight of the 10 charges, voting, 10-2, in favor of acquittal. Castro was convicted of one count of lying to the FBI during the investigation, and he was acquitted on an unrelated extortion charge.

Contact staff writer Allison Steele at 215-854-2641 or asteele@phillynews.com.