In such like circumstances it is best to change the investigating officer and get the case re-investigated. Proper procedure of re-investigation is to file application before the senior officials of police. They usually replace the investigation officer and order for re-investigation of case.
If a criminal case is not properly investigated, it is hard to prove it in the court of law. Because the prosecution has to prove a criminal case beyond the shadow of any doubt. So if investigation is poor, the case has doubts and ultimately it results in poor decision.
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Salman Yousaf Khan (Golra)