He had negotiated with Friedrich Viebahn of the Sicherheitsdienst in Amsterdam that none of the people arrested were to be executed ; Viebahn kept his promise .
He did not feel bound by it in the case of van Hall .
He had negotiated with Friedrich Viebahn of the Sicherheitsdienst in Amsterdam that none of the people arrested were to be executed ; Viebahn kept his promise , although he did not feel bound by it in the case of van Hall .