Omaha, Neb. ? Robert Henderson was not fired as a state trooper because he belonged to the Ku Klux Klan and another white supremacist group, authorities said.

Instead, he was ousted because he could not uphold public trust while participating in such groups, they said.

An arbitrator disagreed, ordering the State Patrol to reinstate Henderson within 60 days and pay him back wages. The state went to court Friday to keep him off the force.

In a summary of the causes for firing Henderson in March, the State Patrol said membership in the KKK “seriously compromised” Henderson’s ability to do his job.

Henderson and the state troopers union appealed and, under its contract, went to binding arbitration, to get his job back.

Arbitrator Paul J. Caffera, a New York lawyer, last week overturned the firing.

He said Henderson was entitled to his First Amendment rights of free speech and that the state violated the troopers’ contract, in part when it fired Henderson “because of his association with the Knights Party … and the Ku Klux Klan.”