Malcolm Menard, a divisional director of security products for Kalamazoo, studied the lay-out of the 700-pupil school(see diagram right) and said: "If there had been a proper procedure for gaining access then Thomas Hamilton would have had more difficulty getting in.
"He could have tried to shoot the door down, but at least this would have created an important delay and allowed those inside time to summon help.
"As it was he was able to walk into the school, through the buildings into the gymnasium."
Mr Menard estimates that it would cost Pounds 4,000 to Pounds 5,000 to install a system the school could easily use once all perimeter fencing was made secure. First the number of entrances would be limited to one. Other doors would be converted to allow exit only.
All pupils and teachers would have identity cards: the teachers' cards would also act as keys into the main entrance. Each card costs approximately Pounds 5.
Anybody who visited the school would have to sign in a register, giving the time they arrived and person they came to see. They would be issued with a pass which would be returned when they left. The receptionist would then log the time. But the cost would go up if all the outlying temporary classrooms were also made secure with doors that can only be opened by special cards -this could be up to Pounds 1,000 a door.
Mr Menard believes that closed-circuit television would not be suitable for a small primary school. He said: "It can be costly, especially as it would require somebody to be watching it full-time if it was to be of any use. It may be more appropriate in a larger secondary school."
Ultimately, without turning a school into a Fort Knox, it is impossible to stop crazed gunmen gaining access, but a security system can help to prevent thefts and contain known troublemakers or intruders. "If there is some sort of registration process it gives out the message that the school is vigilant and secure. An angry parent can be curtailed and an opportunist thief would be put off. The staff will also feel safer at their work," said Mr Menard.
Peter White, chief executive of Kalamazoo, said the Government must provide funds immediately for extra security for schools. "We mustn't have to wait for another disaster to happen before we take positive steps to protect our children."