You may be confusing USPO addresses with geographical or political boundaries. The USPO addresses do not necessarily coincide with other boundaries. I live in one town but my official USPO town is another.
ETA: In contrast, Beverly Hills and Burbank, just to name two examples, are wholly separate cities, each entirely surrounded by Los Angeles City. Hollywood is a district, Santa Monica is a city, etc.
Taking the 110 or even Figueroa south from downtown, you’ll pass through Lomita and San Pedro and the entire harbor before you make it to Long Beach. I do go straight south from LA to Torrance and RPV and PVE twice a month, I also know that taking the 405 will get you through nice communities long before Long Beach as well.
It’s mostly ghetto, but it ain’t all ghetto. South of Sepulveda it starts getting real ritzy, real quick.
Pasadena is in the San Gabriel Valley, which is separate from, and to the east of, The Valley (the San Fernando Valley). Glendale more or less sits on the hills that separate the two valleys. I guess the San Fernando is The valley to Angelinos because most of it is officially part of L.A. city, whereas the San Gabriel valley, though quite well populated, is mostly small independent cities and unincorporated (but often still quite urban) bits of L.A. county. Nevertheless, it is all reasonably considered as part of the L.A. metro area. Most of the cites are not very interesting, but Pasadena itself has a lively nightlife in its Old Town district, and contains not only the Rose Bowl, but the California Institute of Technology (small but very elite) and (sort of) the Jet Propulsion Laboratory.
I should imagine the detective people are talking about was doing his "hoofing" around *downtown* L.A. That is not too unreasonable. Downtown is relatively compact.
But there are hills in West Hills, a decidedly upscale area in the far west of the SFV, roughly north of Malibu but separated from it by that range of mountains that keeps getting mentioned here. I didn’t know about the name change, but around here “Hills” gives just about any name extra panache, which no doubt influenced the decision.
West Hollywood is one of the enclaves, now an incorporated city but formerly an unincorporated piece of L.A. County. It’s also one of the more pedestrian friendly areas. I could readily imagine a detective hoofing it around Santa Monica or Sunset Boulevard doing whatever it is they do do–ask merchants, bartenders, restaurant workers, etc. if they’ve seen or heard anything, I suppose. Beverly Hills is adjacent on the west border of West Hollywood, so it’s a reasonable drive, taxi ride, or even bus ride, but know that the boulevard gets insanely congested going east on weekday afternoons, so any car or bus may not be faster than walking.
The detective could get from the airport to West Hollywood mostly on trains, but it would be a long trip, and the last few miles would be by bus: Green Line from LAX to 103rd St., Blue Line to Union Station downtown, and then Red Line to Hollywood-ish, Santa Monica and Vermont. From there he’d have to take the bus. Among other places within Hollywood, there’s a station at Hollywood and Vine.
And almost entirely devoid of life after about 5pm. I know I know, they are trying to revitalize, but Downtown is just the business district these days. Once the businesses are closed it just the small handful of residents and the homeless. I can’t think of a less interesting area to spend a large amount aimless time in.
Not a bad place to spend a short amount of time in though, if you have an actual reason to be there.
And PRR, just a heads up, public transit from the airport to West Hollywood will likely take you a few hours. A cab or shuttle ride from LAX will be about $35 and take a lot less time than that. If you really want to do public transit fly in to Burbank, you can take a bus to the red line subway and go straight into the stop at Hollywood and Highland and catch another bus down to wherever you’re staying (or walk, it’s likely not too far from there).