Key Verses

1. 5:39Al-Maidah
   فَمَن تَابَ مِنۢ بَعۡدِ ظُلۡمِهِۦ وَأَصۡلَحَ فَإِنَّ ٱللَّهَ يَتُوبُ عَلَيۡهِۚ إِنَّ ٱللَّهَ غَفُورٞ رَّحِيمٌ
   But whoso repenteth after his wrongdoing and amendeth, lo! Allah will relent toward him. Lo! Allah is Forgiving, Merciful.
   In context

   Whoever repents to Allah from the crime of theft and sets right his action, then Allah, out of His grace, will accept His repentance. That is because Allah forgives the sins of those who repent to Him and is Merciful towards them. However if such a matter were to reach the court of law the legal punishment cannot be dismissed by repentance.

2. 42:41Ash-ShuraWarning
   وَلَمَنِ ٱنتَصَرَ بَعۡدَ ظُلۡمِهِۦ فَأُوْلَـٰٓئِكَ مَا عَلَيۡهِم مِّن سَبِيلٍ
   And whoso defendeth himself after he hath suffered wrong - for such, there is no way (of blame) against them.
   In context

   For those who defend themselves, there will be no blame as they had taken their right.