A homeless guy was seen "picking through the uncollected trash for recyclables" in Naked Heat by Richard Castle. When checking for a wounded assailant, there were no "homeless pickups matching her man." Her being, Detective Nikki Heat, of the NYPD.
I think there was a third homeless mention, but lost my bookmarked page, or just thought there would be ~ due to paragraph context ~ a homeless mention, that did not appear, and ditched the bookmark. I was too engrossed in the story to be paying that much attention to my bookmarks.
I vaguely recall that garbage strike ~ um, Sanitation driver strike, employee or union? ~ with trash piling up on the sidewalks of New York for weeks.
I think there is one more Nikki Heat novel. Did a web search. I am confused. Richard Castle is a character in television series, Castle. The character writes a Nikki Heat novel. Nikki is based on Kate Beckett another Castle character who may/may not be a real-life NYPD detective. I think, Richard Castle was called in to assist Detective Beckett on a real-life killing spree patterned after one of Castle's earlier novels.
Yet the book jacket cover is of the actor who plays Richard Castle on the show. Guess more research is needed!