It may be possible to confirm family relationships by comparing test results with Ken or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Family Tree DNA Y-DNA Test 111 markers, haplogroup R-M269, FTDNA kit #B1079 +
Y-Chromosome Test, haplogroup R-Y15103
Mitochondrial DNA test-takers in the direct maternal line:
Family Tree DNA mtDNA Test HVR1 and HVR2, haplogroup K, FTDNA kit #B1079