"Tell Him No," by Scott Turow, in California Schemin', edited by Art Taylor, Wildside Press, 2020.
What kind of work can an 81-year-old private eye do? Running and fist-fighting seem to be out of the question. High-tech is a non-starter.
But one thing an old dude can do easily is be ignored. And that's a very good thing for surveillance.
Tim Brodie, ex-cop, is following Dykstra, a man who wants to sell his business to Tim's employer. Listening in on his conversations turns out to be easy because Dykstra "was the kind who thought they'd invented the cellphone so everyone in the vicinity would know he was important." Boy, do I know that guy.
It's fun watching Brodie watching his target, and then learning what he figured out, and how his boss could use it. An entertaining tale.