Is capital punishment is effective?

Is capital punishment is the real deterrent against heinous crime like rape, murder etc? No doubt that murder, rape or any kind of extreme social abuse(honor killing, religious extremism, mob lynching) is unacceptable in any situation but we didn't have to forget that these kind of incidents are the only reflection of deep rooted perverse ideologies which are inherently prejudiced towards weaker section of our society like women, Dalits, tribals and minority. It is our society, which made them vulnerable. Perpetrators are only a instruments of a crime committed by us. Capital punishment only shows impotency of our system, which is completely failed to provide sufficient justice, rights and freedom to these section, which becomes an only superficial ideal mention in our Constitution. We need to revive our lost ideals in which every person despite cast, creed or gender has an equal say so we can progress towards real civilized society.