NBC renewed “Law & Order: Special Victims Unit” for another season, which seems like life as usual. Dick Wolf and his franchises — including NBC’s Chicago shows — just keep going and going and going.

But the renewal turns the “Law & Order” spinoff — and its star, Mariska Hargitay — into live-action prime-time record breakers. Next season will be the show’s 21st, besting the 20-season record currently held by the mothership, “Law & Order” (1990-2010), and by “Gunsmoke” (1955-75). And the renewal makes Hargitay, who plays Lieutenant Benson, into the longest-running character.

In the TV justice system, it appears franchises are considered especially lucrative and long-running.


Matthew Gilbert can be reached at gilbert@globe.com. Follow him on Twitter @MatthewGilbert.