There always has been disagreement on where Jesus went THAT DAY (since knowing for sure where Jesus went doesn't effect our salvation, it is only of academic consequence).
Both criminals were robbers, but one justly admitted they were both guilty and getting "due reward" (repentant attitude) AND also exonerrated Jesus (fair treatment/love). The other one mocked Jesus. Neither one had time for repentant behavior, but the one that went to "paradise" had the right attitude and an attitude of fairness toward Jesus, but most importantly, he also recognized/acknowledged Jesus as having a KINGDOM/as God's savior).
He probably was saved. Being a just man, he probably only stole out of desperation (for food). I wouldn't like being a victim of someone's desperation, but given the choice, neither would I deny them ANY of the glories of My Lord (Jesus is our advocate before the Father, we should be too, JUSTLY, but with mercy/love). Maybe The Lord included the two robbers in scripture so that we could decide for ourselves what mercy and justice mean in a Godly way.