True story, abbreviated for time. 

San Francisco, about 15 years back now, coming out of the subway following my two teenage daughters. 

A group of tatty half-drunk, half-baked beggars hanging around with their paws out for money. 

And I hear some leering, grubby, smutty comments being directed at my children. 

I sense danger, move a little closer to them. 

And the leerers embolden one another. It gets a bit grubbier, I feel the anger boiling up inside me. 

Then out of nowhere comes this guttural, aggressive, very loud, and very threatening voice. 

It sounds like a lion, and it roars, it truly roars: BACK OFF. 

Everyone jumps. The leerers, the girls, myself, other people passing by turn to see where it came from. 

It's not until this point, as we quicken our step and move up the stairs into the street, that I realise that powerful, guttural, threatening roar came out of me. 

There was no thought behind it, and believe me, I'm not a confrontational or threatening person at all. 

I'm a weed. I'm not brave, and I don't think of myself as anything special on the parenting front. 

It was simple, basic, human instinct, a pre-programmed, primal urge to protect my offspring. 

Any Dad would have done the same. 

So why mention this today? 

It came to mind when I read the mother of Baby Ru now remembers the blow that killed her child. 

She seems to be seeking some kind of credit that she's now ready to tell police the truth, six weeks after the fact. 

And it made me ask: where was your pre-programmed urge to protect your child when it mattered? 

And if it failed you, why not come forward sooner, to seek justice for your child? 

The bottom line all of this makes me ask, where was your parental instinct?