Place your detective cap on and find the killer in the picture puzzle below?

Find The Killer Puzzle

The man with the cast
A) The man must have worn the cast to carry the weapon.

B) Why would a man with the cast go for shopping shirts and coats? Seems his intentions are something else (like killing)

C) The cashier and man next to her are both right-handed and based on blood strains which are on the left side of dead man indicates that killer must be a left-handed person.