According to his daughter , the arrest was triggered by Mikhail 's meeting in 1934 with his elder brother Lester Plesent , who had been living in the USA since 1912 . Other sources suggest that his arrest may have been related to his hiring Richard Pikel , the former secretary of Grigory Zinoviev , who both were also purged and executed
purged
Great Purge
Mikhail Plisetski