PITTSBURGH — A University of Pittsburgh medical researcher arrested in West Virginia agreed Monday to be returned to Pennsylvania to face charges in the cyanide poisoning death of his neurologist wife.

Dr. Robert Ferrante agreed to the transfer in a brief hearing in West Virginia, where he was taken into custody last week. Detectives were to take him to Allegheny County on Tuesday, defense attorney William Difenderfer said. A preliminary arraignment was scheduled for Tuesday afternoon.

Ferrante's wife, Autumn Klein, chief of women's neurology at the University of Pittsburgh Medical Center, died April 20 after suddenly falling ill. Blood tests revealed a lethal level of cyanide, but only after Klein had died and been cremated at her husband's insistence, police said.

Authorities allege that Ferrante used a university credit card to buy more than a half-pound of cyanide two days before his wife became ill. They say he added it to an energy supplement that he gave to her hours after they exchanged text messages about how the supplement could help them conceive a child.

While the criminal complaint in the case indicates that Klein may have been trying to get pregnant, authorities allege that Ferrante also suspected that she was having an affair.

The couple met while she was a student and he worked at the VA hospital in Bedford, Mass. They were married in 2001.