Solution:

The man with the cast

Explanation:
Reason-1: The blood strain is on the left side of the dead man which means the killer is most likely a left-handed. The cashier and man with the cashier are both right-handed.

Reason-2: Why will a man with the cast go for buying shirts/coat? Seems suspicious.

Reason-3: The man with the cast must be carrying the weapon inside the cast.

Solution:

0%. as it will be night in 72 hours and of course, there will be no sun

Solution:

Parents.

Solution:

Terry was born in the Southern Hemisphere.

Solution:

0(zero) off course.

Solution:

The timer of a microwave.

The timer of a microwave generally consists of 4 digits. First two digit for minutes and next two for seconds.
So,
99 indicates - 1 minute 39 seconds
100 indicates - 1 minutes (1:00)

Solution:

The fastest or even the slowest rabbit can only run till the mid point into the given garden. After the mid point, it will actually be running out of the given garden.

Solution:

B

sideways clockwise 1/4 turn

Solution:

C

VIII has taken place of VII.

Solution:

2