Frémont's "field-lieutenant" Merritt returned to Sacramento (known as New Helvetia at the time, so named by the Swiss John Sutter) on June 16 with his prisoners and recounted the events in Sonoma. Frémont either was fearful of going against the popular sentiment at Sonoma or saw the advantages of holding the "Californio" officers as hostages. He also decided to imprison Governor Vallejo's brother-in-law, the American Jacob Leese, in Sutter's Fort. Frémont recounts in his memoirs, "Affairs had now assumed a critical aspect and I presently saw that the time had come when it was unsafe to leave events to mature under unfriendly, or mistaken, direction … I knew the facts of the situation. These I could not make known, but felt warranted in assuming the responsibility and acting on my own knowledge."