1.   The mystery deepened .

2.   The mystery deepens as more witnesses come forward to tell different stories.

3.   The mystery deepens.

4.   But why would anyone want to kill Jack?

5.   The mystery deepened.

6.   Over the next few days the mystery deepened.

7.   Another mystery is also deepening with additional observations.

8.   Ask the journalist from Sao Paulo, and the mystery only deepens.

9.   But as work on the case intensified, the mysteries only deepened.

10.   Now the mystery deepens.