Police in Russia’s second-largest city, St. Petersburg, have arrested a man suspected of stabbing the sister of a member of the Russian parliament’s lower chamber, the State Duma, Artur Chilingarov.

The Investigative Committee said on April 26 that the 59-year-old suspect, whose identity was not disclosed, stabbed the 71-year-old woman, injuring her arm and head in the hall of an apartment block on April 20.

According to the statement, the woman was saved by a neighbor who scared off the attacker.

The suspect, who has a criminal record, was apprehended shortly after the attack. The motive for the attack remains unclear.

Chilingarov, 81, is also a well-known Russian polar explorer.

Aleksandr Bastrykin, the head of the Investigative Committee, has ordered an investigation into the incident.