City of Vice (Channel 4) is not about Oxford, although our local councils' vicious attacks on old people's homes, playgrounds, Radley lakes, rubbish collections, trees and motorists might lead you to think so. In fact it's about London in the mid-18th century. Ah! I hear you cry - another costume drama. Well, it does contain ladies in bonnets and men in wigs but this is rather different from your average prettily old-fashioned drama. London in Georgian times was "a monstrous place", bedevilled by crime, poverty and vice of all kinds.

This series shows how the author Henry Fielding and his blind brother John tried to tackle this morass of wickedness by setting up the Bow Street Runners, an early form of the Bill. The first episode realistically traced their faltering investigation into the murder of a prostitute. It was a convincing mix of documentary and whodunnit, suggesting that the good old days were not good for everyone. And there were very few of those anachronisms that I often notice in period dramas, although I had my doubts about the toast "Here's mud in your eye" and the four-letter word in "You do not f*** with Jack Harris's livelihood".

On the other hand, Lark Rise to Candleford (BBC1) was a costume drama of the pretty, frilly (and pretty silly) kind. Many Oxonians feel proprietorial about the books which Flora Thompson wrote about life in and around her Oxfordshire birthplace, Juniper Hill, simply but eloquently encapsulating a bygone lifestyle. Sadly, Bill Gallagher's dramatisation of her trilogy bears almost no relation to the original. Gallagher's Juniper Hill is a place where everyone wears spotlessly laundered clothes and has beautifully coiffured hair and perfect white teeth. They speak in a wide variety of Mummerset accents and the neighbouring town of Candleford appears to be made of cardboard. The cast includes plenty of familiar (over-familiar?) faces: worst of all being Dawn French overacting as a fecklessly alcoholic Caroline Arless. It was all quite charming but a huge disappointment to anyone hoping for a faithful representation of what Flora Thompson wrote.

Two celebrities were in prison this week (Good! Lock 'em all up!). In fact the presenter of Louis Theroux: Behind Bars (BBC2) is one of the more likeable celebrities, as he seems to be quite modest. In fact, he takes humility to the limit: appearing extremely humble in his hesitant and often naive questions. This elicited some revealing observations from the prisoners in San Quentin, which Louis visited for a fortnight.

It is a tough, noisy place, where the inmates segregate themselves in the exercise yard, keeping groups of blacks, whites and others separate. Louis managed to talk amiably with them, even with the prisoner who confessed that "First I've gotta do 521 years and then 11 life sentences." Many of the inmates are recidivists and several claimed that prison life is easy. The same lifer said: "I'm always going to have food . . . I'm going to be taken care of till I die."

Michael Portillo visited some American prisons for How to Kill a Human Being (BBC2), to see if he could find a painless method of execution. His basic belief is that "if the state's going to kill people, maybe you want to do it as humanely as possible". The former Tory MP admitted voting in favour of capital punishment in the 1980s but changed his mind when there were so many miscarriages of justice.

Portillo discovered that most existing methods of execution have their faults: hanging, lethal injection, the gas chamber and electric chair can all go wrong and cause suffering. Michael thought he had found the perfect method (by depriving the brain of oxygen) for a painless execution but Prof Robert Blecker of the American pro-death movement maintained virulently that "punishment is supposed to be painful".

On a lighter note, Harry's Hill's TV Burp (ITV1) observed: "Jamie Oliver . . . is growing all his own food now. So he doesn't need to go to Sainsbury's."