Shinichi was in USA.
Ray Whitcombe was found dead in his office at his desk.
The police have narrowed the suspects down to three people:
1. Mrs. Barbara Whitcombe, Ray's wife
2. Mr. Jason McCubbins, Ray's business partner
3. Mr. Harold Nichols, Ray's best friend
All three visited Mr. Whitcombe the day of his murder, but all three provided the police,Shinichi with stories of explanation as to the reason for their visit.
Police found Mr. Whitcombe with his wrist watch still on his right arm, a torn up picture of his wife laying on the floor beside the trash can, and an ink pen in his right hand. On the desk, the police found a name plate, a telephone that was off the hook, and a personal calendar turned to the July 5th page with 7B91011 written on it. After examining this evidence, Shinichi knew the culprit.
Who was it?