A new study released Wednesday closely examines several city high schools and how they have maintained a safe environment without metal detectors and harsh discipline.

The New York Civil Liberties Union, the Annenberg Institute for School Reform and Make the Road New York published the study called "Safety with Dignity: Alternatives to Over-Policing Schools."

According to the study, which looked at six public high schools where the populations are considered at-risk to examine school safety, metal detectors are not needed to keep schools safe.

The schools have student safety officers who employ conflict resolution techniques, such as fairness counsels, where both students and teachers discuss infractions and how to deal with them.

The NYCLU says in contrast, there is a growing standard of zero-tolerance policies at most city schools for minor behavioral problems, which are treated as major crimes. The study finds that this, in turn, leaves students feeling unwelcome, penalized by the school system, and feeling that they have no stake in the school community.

The study compared the findings of the six schools with 89 with metal detectors as well as 12 so-called impact schools, which are targeted for more police presence.

"Students, some as young as five, that's kindergarten, were handcuffed or assaulted or taken to jail for infractions like cursing, talking back, writing on the desk, refusing to show ID, or turn over cell phones," said Donna Lieberman of the NYCLU's findings. "And we've seen the emergence of a terrible phenomenon known as the school-to-prison pipeline, where instead of graduation and employment or college, large numbers of children, overwhelming low-income, Black and Latino children, are groomed for jail."

The study claims that even graduation rates are better at these six schools without metal detectors.

The Department of Education says that the study's claim to better graduation rates is false.

The New York City Police Department says major crime in the schools has dropped nine percent this school year compared to last, and is down 44 percent since the 2000-2001 school year. The department says that's because of its partnership with the schools, not because of an absence of police or school safety officers.

Additionally, the NYPD says that metal detectors have helped schools confiscate 22 guns last year and six guns this year.