Well this show was way before my time but that doesn't me I can't enjoy it. I know a lot about Westerns primarily through the Italian cinema and great directors like Sergio Leone making such classics as "The Good, The Bad, The Ugly".
In fact during this time of 50-70s the Western boom was in full on television. Even though the plots were the same in many western (clear cut good guys, bad guys, easy women, bar saloons, cases involving crimes and lots of shootouts) depending on which one you saw, you'd get something different. Lawman was one of those thirty minutes Western shows like Chuck Connor's "The Rifleman" giving you a lot of action, acting and story and packing it in thirty minutes. Impressive to say the least because obviously in the one hour shows like Gunsmoke and Bonanza the writers and actors could pursue more complicated and longer story arc.
Anyway, this is largely a one man show for the most part, John Russell is great as Dan Troop doing his best to keep
a troubled down clean. He meets Johnny McKay a farmboy of sorts who becomes his deputy, Mrs. Lemp the town's cook and hostess who lost a husband.
As I said it's a one man show at least for the first season, there's clearly a lot of mentoring down by the more experienced Lawman as Johnny shows his inexperience many times: Losing prisoners, being naive to bad women, being ambushed by criminals etc. Thus Dan Troop often is the hero of the day but Johnny does help him by holding criminals in jail, running errands, keeping a watch of the town while Dan is away.
It's sad that this show doesn't have a commercial DVD release there are couple of episodes released on VHS but Warner Brothers has largely forgotten this gem as they have other classic shows like China Beach. It's mind0boggling but if you get a chance to see this show then see it.