"But the sea-green Ford was sitting there with its engine running!"

"Meaning," nodded Jake, "that the driver pulled in and made a fast dash
into the store for a newspaper or a pack of cigarettes."

"I understand. Your man could get caught. Or," added Jimmy thoughtfully,
"the owner might even take his car away before we got there."

Jake nodded. This one was going to make it easy for him.

As the days wore on, Jimmy became more selective. He saw no point in
reporting a car that wasn't going to be used. An easy mark wedged between
two other cars couldn't be removed with ease. A car parked in front of a
parking meter with a red flag was dangerous, it meant that the time was
up and the driver should be getting nervous about it. A man who came
shopping along the street to find a meter with some time left by the
former driver was obviously looking for a quick-stop place--whereas the
man who fed the meter to its limit was a much better bet.

Jake, thankful for what Fate had brought him, now added refinements of
education. Cars parked in front of supermarkets weren't safe; the owner
might be standing just inside the big plate glass window. The car parked
hurriedly just before the opening of business was likely to be a good bet
because people are careless about details when they are hurrying to punch
the old time clock.

Jake even closed down his operations during the calculated danger
periods, but he made sure to tell Jimmy Holden why.

From school-closing to dinnertime Jimmy was allowed to do as he pleased.