Google the film writer and director David Ayer and you get the standard results: an IMDb dossier, a Wikipedia page, assorted reviews of his past movies, and various news items about his future releases. None of the links suggest that Ayer is building one of the most vital and distinctive bodies of work going.

The oversight is understandable. His résumé is full of titles that raise eyebrows: the inaugural “The Fast and the Furious,” the film adaptation of “S.W.A.T.,” and a Keanu Reeves actioner that barely made a mark called “Street Kings.”

There is one exception: “Training Day,” from 2001, for which Ayer wrote the script. Largely favorable reviews and an Oscar-winning performance from Denzel Washinigton have made it Ayer’s most prominent credential by far. Even in films where he writes and directs, his movies are usually marketed under the tagline “From the writer of ‘Training Day.’”

Nevertheless, almost all of his works evidence a singularly fascinating, uncompromising vision. Just as John Ford returned again and again to the 19th century West, Ayer’s world is contemporary Los Angeles. Not Hollywood and points West, but South Central, Compton, the Rampart district — the unglamorous side of the sprawling city, where police and gangs collide, commingle and kill one another. His films are deep dives into a domestic war zone that goes largely ignored.

Few other filmmakers are capable of immersing audiences as deeply into the treacherous bureaucracy of the L.A.P.D., or as authentically into the brutal realities of gang life. If you’ve ever seen the eye-opening documentary “Bastards of the Party,” which investigates the history of L.A.’s dominant gangs and, in doing so, humanizes the landscape, Ayer’s world will look and feel fully convincing, even accounting for the artistic license he invokes in the name of drama. In fact, the central figure of “Bastards” is former gang-member turned filmmaker Cle Sloan, who has appeared in a number of Ayer’s films in small roles.

Where to start with Ayer’s work? For those who haven’t seen it, “Training Day” is his most accessible movie. For those who have, “Harsh Times,” which was his directorial debut (and which was Christian Bale’s first role after “Batman Begins”) shows the full, unfiltered power of Ayer’s vision. “End of Watch” which I wrote about last August is almost literally a ride along-style tour of Ayer’s world. “Dark Blue,” which was almost completely missed when it debuted twelve years ago, is flawed but thoroughly captivating. And even “Street Kings,” which is not Keanu Reeves’s best work, is nevertheless well worth watching, and what convinced me that even the least coherent of Ayer’s work is never less than fascinating.