All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
First of all, you have to advise this person, perhaps your advice would lead to him repenting from the sin he is committing. The Prophet, sallallaahu ‘alayhi wa sallam, pointed out that the essence of the religion is to offer advice. [Al-Bukhari]
Additionally, the Prophet, sallallaahu ‘alayhi wa sallam, commanded the Muslim to support his fellow Muslim whether he is oppressed or an oppressor, and clarified that supporting him as an oppressor is by preventing him from oppression and transgression. [Al-Bukhari]
The ruling of accepting the shoes he gifted you is the same as that of accepting the present from a person whose money is ill-gotten, which is detailed in Fatwa 86836.
Allaah Knows best.