The RC church in the US can and does deny funeral masses to certain people. Gotti, Frank DeCicco and Castellano were all denied this rite.

This doesn't mean the church denies they will be forgiven by God for their sins. That's between them and God. They are granted a funeral service, but not the full rite of Mass.

Canon 1184 of the Code of Canon Law, is ''The following are to be deprived of ecclesiastic funeral rites: notorious apostates, heretics and schismatics; persons who have chosen the cremation of their own bodies for reasons opposed to the Christian faith; other manifest sinners for whom ecclesiastic funeral rites cannot be granted without public scandal to the faithful.''

In the cases of Gotti and Castellano it was to avoid the appearance that the church condoned their criminal activity, which falls under the last reason of the Canon.