He then joined the law firm of Chase, Rotchford, Downen & Drukker, where he practiced for 11 years and became a partner.
In 1982, Kaus was on the ballot for retention by the voters, along with fellow justices Cruz Reynoso and Allen Broussard.
However, the state Supreme Court had become controversial due to the growing perception by many that Brown's appointees, particularly Chief Justice Rose Bird, were liberal ideologues whose rulings were political.
While on the bench, his notable cases include his concurring opinion in National Audubon Society v. Superior Court (1983), concerning the conflict between the public trust doctrine and appropriative water rights.
In 1984, he wrote the opinion for a unanimous court in People v. Bledsoe that rape trauma syndrome is inadmissible as evidence of the crime.
He also mentored then-associate Jeffrey Ehrlich, who would later rise to national prominence for arguing cases in the United States and California Supreme Court.