Metal detectors are to be installed in hundreds of secondary schools in England to try and stop some people bringing knives into the classroom.
Although knife crime is rare, research shows that some young people are carrying knives to make themselves feel safer.
The detectors used in schools will be similar to the ones used in airports.
In America, scanners are very common in high schools, and even kids at primary schools get checked for weapons.
Top police officers and head teachers are supporting the plans to use them in more schools in this country.
The Home Secretary Jacqui Smith said it would be a "good idea" to look at how they could be used.
Ms Smith said she wanted young people to know that it didn't make them safer to carry a knife.
The scanners could be brought into schools in cities like London, Liverpool, Manchester and Birmingham.