Tracing the calls made to Baluchi's phone number, authorities discovered that he had received 16 calls from 28–30 June from a pre-paid Voicestream mobile purchased in Manhattan on 4 June. The phone was deactivated on 11 July, and authorities allege it belonged to Atta, while Baluchi insisted that he only ever spoke with Shehhi, who had hired him. Around this time, Baluchi complained to Mohammed that he couldn't do all this additional work himself, and his uncle told him that Mustafa al-Hawsawi would co-ordinate with him to act as an assistant.