BOSTON (CBS) – By now, you’ve heard the sorry story of Manti Te’o, the Notre Dame football star who earned widespread media coverage and sympathy after the tragic death of his girlfriend last year.

Listen to Jon’s commentary:

But it turns out the girlfriend never existed. She was an elaborate hoax, one that Te’o denies participating in, despite significant evidence that he did.

It’s all very odd and yet another discouraging example of how duplicitous people can be.

Not that we needed a reminder.

Lance Armstrong, a hero to many for his work fighting cancer, turns out to be a pathological liar and bully. He’s the reigning king of a pantheon of sports heroes who’ve been caught looking us right in the eye and lying.

But the sports world has nothing on the business world, home to a shameful litany of Bernie Madoff wanna-bes and assorted frauds. The news business has its share of fakers and phonies.

And politics?

Two words: John Edwards.

And you definitely don’t have to be a celebrity to be untrustworthy. Hardly a week goes by without a fresh story of someone who faked a terrible disease to scam their generous neighbors, or some other con-artist who exploited the vulnerable.

So maybe you’re wondering – how do you know who you can trust?

Let’s face it, everyone has their secrets, and maybe we can never fully know what’s in someone’s heart. But secrets don’t mean someone can’t be faithful, a friend who doesn’t disappear when times are tough.

You can tell when someone is honest – if they’re willing to break small promises, you can assume the big stuff is expendable as well. And while true love isn’t always easy to define, if it’s accompanied by faithfulness and honesty, chances are it’s the real thing.

Love, faithfulness, honesty – that’s how you know if you can trust someone. But it can sometimes be hard to find in people.

That’s why so many people have pets.

You can listen to Keller At Large on WBZ News Radio every weekday at 7:55 a.m. and 12:25 p.m. You can also watch Jon on WBZ-TV News.

Jon Keller