Rashi in Sanhedrin 51b writes that Capital Punishment will be reinstated after the coming of Moshiach.
I believe the Meshech Chochmo in Parshas Shoftim (I’ll bli neder look it up) explains that there are two types of redemption, depending on whether we merit the early redemption or if we have to wait until the end of the golus without being zoiche, and I think he differentiates between the two regarding the possibility of sin.