Bicycle detail

When I drove home around 8pm, there was a man 40-50 years old, African-American, wearing a green sleeveless Jersey, sitting on my stairs (inside my gate). As soon as I parked the car, he left. He went into my neighbors driveway (not visible to me) and then walked out, wearing just a white wife-beater. I kind of stared at him as he left. My neighbor across the street was watching him, too. I checked the lock on my bike and it was still locked. I went inside. I left the house around 9:45pm and that's when I noticed it was stolen.