NORRISTOWN, PA. ? A University of Pennsylvania professor was charged Monday with bludgeoning his wife to death in their suburban kitchen after she told friends she was going to divorce him.

Rafael Robb, 56, taught economics at the Ivy League school and is an expert in game theory, the study of how people and governments make decisions by calculating what others might do. Game theory is used to understand consumer behavior and is also used by military experts to develop nuclear warfare strategies.

Robb told investigators he was in Philadelphia when his wife was killed Dec. 22. But prosecutors doubted his alibi.

District Attorney Bruce Castor said the crime scene was arranged to make it look as if Robb’s wife, Ellen Robb, was killed during a burglary.

Robb “lied to the police about an obvious motive for this murder, his knowledge of his wife’s recent plans to divorce him and obtain a significant portion of his wealth,” police said in court papers.

He was arraigned on murder charges and jailed without bail.

Authorities said Ellen Robb’s injuries were so extensive they initially thought she was killed with a shotgun blast to the face. The murder weapon has not been found.

Ellen Robb, 49, had told relatives and others that she had hired a divorce lawyer and was expecting $4,000 a month in spousal support, prosecutors said in court papers.

Robb had said he took the couple’s 12-year-old daughter to school that morning and last saw his wife alive before driving to work. He said he returned home later that day and found her body.