So, reluctantly, he turned back into the house.

A glance over the moonlit lawn revealed no sign of the fugitive.
"I'm sorry," he said to Standish, as he shut the door behind him and patted the fidgetingly excited Bobby Burns on the head.

"I may never have such a good chance at him again.

And your promise of a confession was the thing that made me arrest him.

Your evidence would have been enough to convict him.
And that's the only thing that could have convicted him or made it worth while to arrest him.