A couple went on for a climbing trip

A couple went on for a climbing trip.
But only the husband returned from the vacation
and said that his wife slipped off while climbing and died.
On investigating, the local sheriff arrested him saying,
"Your travel agent called. You murdered your wife."

The man did not inform anyone about the trip.
Then how did the agent was so sure that it is a murder?

Click here for Answer

The man bought only a one way ticket for his wife,
whereas he bought a two way ticket for himself.
It means that he was sure that he will be returning alone.