The crime drama, especially as done by CBS, was primetime television’s most bankable drama format for about a decade — but that seems to be changing.

Sure, skeins like “NCIS” and “Criminal Minds” continue to perform well for the Eye, but the net hasn’t seen quite the same success the past two years with “Blue Bloods” or “Person of Interest,” crime shows that took the genre in slightly different directions. Elsewhere, NBC’s copshow “Prime Suspect” was rejected from the start in the fall, and ABC’s “Body of Proof” remains a modest performer in its second season.

But perhaps the best indicator of this trend is that over the last 12 months, spinoffs of three venerable crime shows — “Law and Order,” “Bones” and “Criminal Minds” — have failed to click with auds. Sure, “Bones” offshoot “The Finder” just bowed last month, but the early returns haven’t been encouraging.

Fox used “Bones” to funnel viewers into “The Finder” when it premiered on Jan. 12, but the newbie settled for a 1.7 rating (compared with a 2.4 for its lead-in). And in its second week, even with a big lead-in from “American Idol” (5.7 rating), “Finder” grew to only a 2.2 — still fourth in its Thursday timeslot.

NBC tried to breathe life into the fading “Law and Order” franchise with “Law and Order: L.A.,” but the show’s reboot last April opened with a thud (1.5) and its run ingloriously ended with burnoff episodes in July. It was the third “L&O” spinoff in the U.S., but only “SVU” remains on the air (“U.K.” continues in Blighty).

And at CBS, “Criminal Minds: Suspect Behavior,” fronted by Forest Whitaker, dropped off sharply from its ancestor, which preceded it on Wednesdays. Auds tuned in for the premiere (3.3 rating), but the show dropped to a 2.4 the following week and was hovering around a 2 when it wrapped its 13-episode run.

It wasn’t surprising to see the nets order more spinoffs in the wake of CBS’ success with “NCIS” and “NCIS: Los Angeles,” with the latter going strong in its third year. But that one may just be the last we’ll see work for a while.