Can anyone explain in such a huge murder case,why there's no forensic evidence ?
There is forensic evidence you just ignore it because it establishes Jeremy is guilt y and you hate to face that reality.
The forensic evidence establishes Sheila didn't load a gun, didn't fire a gun, didn't beat anyone, didn't kill anyone else and didn't kill herself.
The forensic evidence proves someone else was at WHF who killed everyone and then left the scene. Since you prefer believing Sheila killed everyone you ignore it. It amounts to dishonesty on your part to deny it exists. Saying you don't believe such evidence though you have no way to refute it would be one thing. But you always go the extra mile and say it doesn't exist. You not only demonstrate your extreme bias when you do that but dishonesty because you have been reminded countless time it exists and when challenged to refute the evidence you have failed miserably.
His lawyers don't have the luxury of living in fantasyland they have to face this evidence and are forced to try to find a way to refute it. To date they have been unable to do so and unless they can they have no hope of establishing Jeremy's innocence and getting him out of prison.