If your son was not a full-time student, then no, you cannot claim him as a dependent. He is too old to be a qualifying child, and earned too much to be a qualifying relative.
IRS interview to help determine who can be claimed:
https://www.irs.gov/help/ita/who-can-i-claim-as-a-dependent
https://ttlc.intuit.com/questions/3113432-who-can-i-claim-as-my-dependent
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This answer has been verified for accuracy by an Intuit expert employee
