Last Night's Viewing: The Repo Man, Channel 4 12-Year-Old Lifer (the story of Paul Gingerich), Channel 4

Feeling better because of the spring sunshine? Daring to hope that things are getting better at last? If so you might want to avoid Sean James. "We don't live in a civilized country at all," Sean said gloomily at the beginning of Arron Fellows' film about his work. "The human race is shit."

Then again you'd probably want to avoid Sean anyway – at least in his professional capacity – because Sean is a repo man, the last resort for finance companies who have run out of patience with dilatory payers and defaulters. Sean is the guy who turns up at seven o'clock in the morning with a tow truck and takes the car that you've fooled yourself into believing is your property, but which actually belongs to someone else altogether.

It's not a job to give you a warm view of the human race. Although this first episode of The Repo Man featured a man who reacted to the removal of his car with an almost beatific serenity ("What I'm going to do now is get my guitar and praise God," he said, beaming happily), he wasn't exactly typical. You could see his face for one thing and most of Sean's customers had opted to have their features blurred into anonymity.

It made them look like the victims of some strange virus, which fuzzed the face into a blob, and simultaneously induced bouts of swearing and an overwhelming sense of righteous indignation. "I suppose you're proud of yourself, are you?" Sean recalled one woman saying to him when he repossessed her Range Rover. "We've just got back from Disneyland and you've spoiled it for us." Sean took the view that if you're behind on your car payments, a trip to Disneyland shouldn't be your first priority.

Sean has a softer side, though even the soft side has hard chunks in it. He loves to spend time with his 10-year-old son, for example, teaching him how to use nunchucks or helping him build a Lego prison cell. And he has a sideline in painting what he calls "muriels" on children's bedroom walls. Standing back from a freshly completed muriel of Thor smiting someone with his hammer, Sean confessed that this gave him a satisfaction repo work didn't: "You get a bit of praise for once, instead of someone chasing you round with a baseball bat trying to cave your head in."

Unfortunately, just as you were beginning to warm to Sean, he let rip with an outburst about "scumbag kids" and foreigners who "come over and go straight on the dole". "Rant over," he said sheepishly at the end, but you were left thinking that if that's what he says on camera, he might be a lot less charming in his unguarded moments.

In 12-Year-Old Lifer, we got the story of Paul Gingerich, a central-casting small-town boy who ended up with a 30-year sentence after helping an older friend shoot his stepfather. Boy A was 15-year-old Colt Lundy, named after his father's favourite handgun, who persuaded Paul and another friend that they should head for Arizona in his stepdad's car. Before they went, they used the man's own guns to murder him.

Zara Hayes's film talked to relatives of the dead man and to Paul and Colt's parents, and implicitly arraigned a system that had charged and tried children as if they were adults. Colt is now feverishly bodybuilding to prepare for the moment at which he will be transferred from juvenile prison and find himself at the mercy of "older guys that are not so playful".

Paul has just successfully appealed to be retried as a juvenile, where you would hope that someone might belatedly recognise just how large the gap between 12 and 15 can be. Indignation at the retributive simplicities of the American legal system should have been tempered by the realisation that exactly the same thing could, and has, happened here.

twitter.com/tds153