Ms Murphy, who is 62, has found the children on her back doorstep "abusive", "aggressive" and "out of control". "If you see four or five kids coming at you, you cross the road. They can sometimes be kids that are all right on their own but, because they're in a crowd, they're more aggressive. We'd need a policeman in every street to control the problem."
Local police in Strathclyde believe that children on the streets at night can be a danger to the public but also at risk themselves.
In a pilot scheme in Hamilton, police rounded up children and sent them home. The move has, somewhat surprisingly, won the support of the majority of residents and parents, though not necessarily the children concerned, who reportedly feel their freedom to roam has been taken away.
In one incident, a four-year-old boy was found wandering the streets at 9pm on a winter evening. An eight-year-old girl was discovered running errands for her mother well after dark, and a 13-year-old boy was found who had run away and threatened to hang himself. The police are not merely concerned with stopping children making a nuisance of themselves, but also returning home those who may be at risk.
Mother of three Anne Gibson, 33, says she has noticed a marked improvement on the Hamilton estate, where she lives. "It has been a great success. The streets are now awfully quiet, and you're not trying to fight your way past cheeky kids if you go out at nine o'clock."
But the main problem as Ms Gibson sees it is the lack of anything affordable for young children to do. "It seems that, for my kids, there's nothing to do unless you want to pay for it." One positive thing to come out of the scheme, she says, is that now she knows her children will always head home to play in the garden before the police start to do their rounds at 9pm. "Now I know where they are, and if anything is wrong, which is a relief."
Parents often don't know where their children are or who they're with. With the older ones particularly, they may tell them one thing then do another. In some cases, says Karen Murphy "parents are afraid of their own kids", and simply cannot control them. To make matters worse, children see themselves as untouchable. "I saw one kid daring an old man to hit him. He said, `You hit me, and I'll get you jailed'."
Nicola McDonald, 27, who lives on another Hamilton estate subject to curfew and has a young child, is less enthusiastic about the initiative. "In theory the curfew worked, but you can't take something away from the kids without giving them something else. You can't just bang them with their parents, and sweep the problem under the rug, you have to give them an interest."
The streets have unquestionably been cleaned up and if underage drinkers and smokers are still drinking and smoking they are doing it out of sight, but McDonald believes that the children need somewhere to go to "develop social skills", and the younger ones need a play area that is off-limits to the older children.
Local children have not reacted well, she says. "They feel their freedom has been taken from them and they are angry. The street is their whole world," she explains. "It's a territorial thing." Boredom and lack of alternatives obviously play their part, which is why the police are now pushing to open a series of youth clubs that have been designed, and even named, by the children who will be using them. Three estates took part in the project, where tenants had asked for action to be taken against crime, and early figures show that crime among under-16s plummeted by a third, while complaints from the public concerning youth disorder were halved.
The initiative has sparked keen interest from within the UK and abroad. And while Strathclyde police are reluctant to give a final verdict on the success of the scheme, until they have studied a report on it conducted by Stirling University, Chief Inspector Caroline Scott confirmed that it had got a "very positive reaction" from the public.
"This is not about saying that no young people can be on the streets," said Sandy Cameron, head of social services at South Lanarkshire Council, "but the streets can be risky for young kids, and groups of gathered youngsters can be intimidating for young and old alike."
Strathclyde police are considering expanding the scheme to neighbouring communities and say they have no shortage of estates wanting to take part. And the Home Office, which has kept a close eye on the project, is optimistic about its possible knock-on effect. Susan, 30, who lives on the Becklow estate in west London with her husband and 10-year-old son, said she would welcome similar action by her local police force.
"If you get a gaggle of kids there's usually some sort of trouble," she says, and although the estate is far from a no-go zone, she admits she finds it intimidating to walk through the groups of teenagers that hang around the blocks. "Even as an adult I feel `Oh God', and tend to cross over the road. They probably wouldn't say or do anything, but it's still uncomfortable."
There is a minor drug problem on the estate, she says, but controlling the situation is made particularly difficult by the fact that many of the children hanging around do not even live on the estate, so no-one knows who they are.
Nearby, the White City estate in Shepherds Bush is one of nine selected to pilot the curfew scheme. Despite attempts to clean up its reputation, the estate is still notorious for problems including drugs, unemployment, muggings and break-ins. Ten thousand people live here, housed in 2,200 post-war tenement flats within half a square mile.
PC Doug Milne, who will be helping to implement the scheme with his officers, does his best to show the estate in a good light, being extra jolly with the locals, zealously patting young children's heads and pointing out a few green areas free of litter. Then he spots three teenage boys hanging around near the local shops. They look suspicious as PC Milne approaches. "We see more of you lot around here now," says one. "You're always raiding our houses." Milne smiles cheerfully and asks them if they shouldn't be at school today. "Been excluded," says his friend. So how would they feel about a curfew scheme? "Wouldn't bother us. We'd just ignore them or come back 10 minutes later - there's nothing they could do about it."
His friend chips in, "If my mum tells me to stay in, I do. I don't need you lot to tell me." PC Milne looks embarrassed. I wouldn't fancy his chances, if and when he and his officers have to round up teenagers like this and force them to go home.
Walking through the deserted stairwells scattered with old roaches, Milne says there are more problems with young children truanting during the day. He admits that there aren't actually that many 10-year-olds hanging around after dark, vulnerable, threatening or otherwise. "We'd have taken 10-year-olds home to their parents before this curfew anyway," he says.
So that leaves the teenagers. It seems a little unfair that adolescents should fall under police scrutiny just because of where they live, especially when middle-class teenagers are allowed to "hang out" in the nearby areas of Hammersmith and Brook Green. PC Milne admits: "These teenagers need somewhere to go, especially on an estate where there isn't a great deal to do." Giving them somewhere to go in the evenings, rather than penalising them simply for staying out, may have been a wiser solution. "The scheme will certainly please people who complain about young people hanging around," says PC Milne. "But it's a trust thing; how will it affect community feelings if we're continually telling them to go home?"
You can't imagine it's something he looks forward to implementing; the curfew won't exactly improve an otherwise delicate relationship. As Milne says: "In an area where trust in the police isn't very high, we'll have to tread extremely lightly."
Some names have been changed. Additional reporting by Emma CookReuse content