They are nicknamed the "campus cops" in East Renfrewshire as they meet and greet pupils with a cheerful "Good morning!" on their way into school. But their jobs don't stop there.
Mike Greville, Mark Armstrong and Susan Greer are the uniformed branch of a new Scottish Executive-funded initiative in the authority called the SSPC - School, Social Partnership and Community initiative.
It means that the three police officers, all experienced in community policing, are based permanently for the next two years in three of the authority's secondaries, with responsibility for the remaining four secondary schools and links to associated primaries.
While school-based police officers are not a new phenomenon in Scottish schools, they are rare. East Renfrewshire Council believes this campus initiative is breaking new ground in that the police are part of a team that includes social work, community service, and education staff.
A spokesman for East Renfrewshire Council said it was adopting a Danish model of trying to steer young people away from possible and potential trouble.
"The campus officers are in the schools to act as positive role models for young people, to identify and work with kids who are vulnerable, to boost school safety, to liaise with the community, and to develop social skills and responsibility by working with school, social work and community service staff," he said.
In practice, that means that PC Mike Greville, based at Woodfarm High but also covering St Ninian's High, is addressing litter problems by liaising with cleansing and environmental staff and exploring with young people where bins should be sited.
"It might sound way down the scale and not important to a police officer, but to the community it means a lot - and that impacts on the school," he said.
He is also monitoring road safety, such as keeping the bus stops clear of parked cars.
Within the school he removes the most intimidating parts of his uniform, such as body armour, baton and handcuffs. His desk is in the behaviour support teachers' office and he speaks to classes on citizenship. He has also initiated a Heartstart emergency life support programme for pupils.
"School discipline is very much left to the school," PC Greville says. "I am not there as the bogeyman - I have only got a part to play and will support the behaviour support team."
Nevertheless, he has access to local intelligence about potential criminal activity which he can then share and, hopefully, nip potential trouble in the bud.
"I work closely with learning support, behaviour support, the school educational psychologist, the youth counsellor, home-link workers and health professionals.
"It means that no one is just going away and doing their own thing. Our team meeting discusses everything; information is getting put on the table, and we can feel free to pass it over."
PC Greville also has statutory powers of search should a pupil ever be suspected of carrying an offensive weapon. Teachers can only request that a pupil turn out his or her pockets - a scenario which can lead to delay.
At 49 years of age and with 27 years of service, PC Greville is the most experienced of the three campus officers.
Almost 20 years ago, he won a Churchill scholarship to study community policing in the high crime areas of the United States. On his return, he was pitched into the "cultural melting pot" of Bellahouston Academy in Glasgow, an inner-city school of 1,500 pupils.
In the late 1980s, he was able to adapt some of the community policing techniques he had seen in the States and, although not based at the school, he worked very closely with senior management and other staff at the school.
For some time at Bellahouston, there had been concerns about trouble simmering under the surface which was having an impact on attendance.
Eventually, PC Greville says, through working with school staff and members of the community, the police were able to build up a picture of a group of youths - not pupils - who were operating an extortion ring and intimidating pupils on their way to school.
Prosecutions followed and the courts agreed to make an exclusion order part of the bail conditions of the group. It was an idea ahead of its time in Scotland.
PC Greville believes Scotland is at least 10 to 15 years behind the States when it comes to school-based policing.
"We're playing catch up, but at least it's started," he says. "This is definitely the way forward."
* Meanwhile at Northfield Academy in Aberdeen, Constable Keith Molloy, the school's police officer for the past four years, is to hand on his baton to Constable George Craig.
The Aberdeen initiative, which has attracted the personal interest of the First Minister, aims to tackle crime reduction, youth disaffection, social exclusion and anti-social behaviour in the Northfield area of Aberdeen.
Constable Craig said he looked forward to being "a positive influence" on the school.