He joined the FBI in 1979 and In 2001, Robert Hanssen was sentenced to 15 consecutive life sentences in federal prison (without parole; there’s no parole in the federal prison system). He’s currently “living” the rest of his days in at ADD Florence, a supermax prison near Florence, Colorado. ADX Florence is basically Arkham Asylum. Built for supervillains.
Nerves of clay. If you don't care you can't be flustered.
It might be instructive to consider what conditions he experienced working there that led him to conclude his co workers weren't even worthy if contempt. However it was likely just high functioning alcoholism and white privilage.