The Maltese Falcon by Dashiell Hammett:
Spade walked up Sutter Street to Kearny, where he entered a cigar-store to buy two sacks of Bull Durham. When he came out the youth was one of four people waiting for a street-car on the opposite corner.
Spade ate dinner at Herbert’s Grill in Powell Street. When he left the Grill, at a quarter to eight, the youth was looking into a nearby haberdasher’s window.