Moscow (CNN)A prominent Russian historian appeared in court in St. Petersburg on Monday in a grisly murder case that has grabbed headlines across the country. Oleg Sokolov, a 63-year-old professor at St. Petersburg State University, is the suspect in the death of one of his former students, Anastasia Yeshchenko. The celebrity academic was pulled out of Moika River, in the heart of the historic city, over the weekend. A backpack he was carrying contained a pair of severed arms and a nonlethal handgun. Law enforcement officials told the Russian state news agency RIA-Novosti that Yeshchenko’s dismembered body was found in Sokolov’s apartment. The victim was 24, according to the news agency. In court on Monday, Sokolov told the judge, “I repent deeply,” according to local media news outlet fontanka.ru.