There are three different kinds of Baptism.
Water and the Spirit — we are most familiar with this one.
Baptism of Desire — in a person’s dying breath they convert.
Baptism of Blood — quite obvious, they die giving their blood for Christ.
The Good thief had both the Baptism of Desire and the Baptism of Blood.
The good thief didn't die "giving his blood for Christ", he was executed for being a thief.