Yes, if he lived with you all year and had less than $4050 of income.
A person can still be a Qualifying
relative dependent, if not a Qualifying Child, if he meets the 6 tests for
claiming a dependent:
1. Closely Related OR live
with the taxpayer ALL year
2. His/her gross taxable income for the year must be less than $4,050 (2016-17)
3. The taxpayer must have
provided more than 1/2 his support
4. He must be a US citizen or resident of the US, Canada
or Mexico
5. He must not file a joint
return with his spouse or be claiming a dependent of his own
6. He must not be the
qualifying child of another taxpayer