A blind beggar in the Bronx has a
brother who is a lawyer and lives in Boston.

The lawyer asserts he has no blind
brother who resides in the Bronx,
according to his familiy tree.

Both are telling the truth,
so how can this be?

These siblings have the same
parents both father and mother,
and not in the habit
of denying one another.

What's the relation between beggar to lawyer. Remember, the blind beggar is other than brother.

hint 2
Both assertions are correct.

hint 3
Both beggar and lawyer are telling the truth about their family relationship.