Protesters gather at the University of Texas last year in Austin. (Ralph Barrera/Associated Press)

Daniel Webster is a professor of health policy and management at the Johns Hopkins Bloomberg School of Public Health and the director of the Johns Hopkins Center for Gun Policy and Research. Ronald Daniels is president of Johns Hopkins University.

Texas this year became the eighth state to require state colleges and universities to allow civilians with permits to carry concealed guns in public places. As a result, the University of Texas at Austin — a school that 50 years ago suffered the trauma of the nation’s first campus mass killing — must allow guns to be brought onto campus.

To those behind the campus-carry movement making such inroads in Austin and other state capitals, that’s a good thing. This effort is based on the belief that allowing more guns in public places will lead to less violence. But does the evidence support this premise? A new report released by Johns Hopkins University, with co-authors from Stanford University and the University of Massachusetts at Boston, surveys the best available research and says no.

Proponents of expanding civilian gun-carrying argue that many mass shootings occur because perpetrators know victims will be unarmed and defenseless due to legal restrictions on carrying in public places. They also contend that citizens, if armed with firearms, can effectively end the carnage of active shootings.

But the latest research on mass shootings, much of it detailed in a new book by report co-author Louis Klarevas, tells a different story. First, the overwhelming majority of fatal mass shootings occur in places where guns are allowed. Second, when rampage shootings do occur, gun-wielding civilians rarely are able to stop them. Effective and responsible use of a firearm under the conditions of an active shooter requires significant training and the ability to make good decisions and shoot accurately under the most challenging circumstances. Even some trained law-enforcement officers perform poorly under such circumstances. These facts explain why the best research shows that right-to-carry gun laws do not decrease mass shootings or the number of people shot in those incidents.

Campus-carry proponents have turned to another equally specious argument: If guns were permitted at colleges and universities, victims of sexual assault could use them to fend off their attackers. This argument, too, is starkly at odds with the best evidence. If carrying a gun were effective in warding off would-be rapists in a nation where civilian gun-carrying is not uncommon, you would expect many to report using a gun in this manner. Yet a study by Harvard’s David Hemenway using data from the National Crime Victimization Survey from 2007 to 2011 showed that out of the 62 cases in which a respondent reported being a victim of a violent crime and using a gun in self-defense, not one involved a sexual assault. In fact, once a crime is in progress, the use of a gun by a victim in self-defense did not affect his or her risk of being injured one way or the other.

The fact is that the evidence for guns as a deterrent to campus crime is weak or nonexistent. And profound evidence shows that the college environment is particularly ill-suited to gun possession.

The risks and interconnectedness of violence, alcohol abuse and reckless behavior are elevated among college-age youths. The frequency of binge drinking among college students is a deep and enduring problem, and the evidence from studies of criminal assaults both outside and inside the home and comparisons of victims who are treated at hospitals for nonlethal assault-related injuries with homicides shows that the presence of firearms dramatically increases the risk of death and injury during altercations. Freely inserting firearms into this environment is a recipe for tragedy.

Similarly, a recent study of campus shootings conducted by Everytown for Gun Safety (founded by former New York mayor Michael Bloomberg, who also is a major donor to Johns Hopkins University) shows that the vast majority are neither mass shootings nor active-shooter incidents but instead involve situations where the presence of guns is shown to be far more lethal — interpersonal disputes, targeted attacks, accidents and suicide.

Suicide attempts that lead to hospital treatment or death rise dramatically and peak during the college years, and they have been increasing in recent years. A large body of research ranging from comparative studies of households where suicides have occurred and ones where they have not, studies examining the association between states’ suicide rates and gun ownership, and evaluations of laws designed to restrict firearms access of high-risk individuals clearly shows that access increases the risk of suicide. Should this not be a serious consideration for those advocating for guns on campus?

A university should be a place where ideas are celebrated and contentious views are faithfully explored. Here, we seek evidence that can shine light on our darkest challenges.

As the president of Johns Hopkins University and a gun violence researcher at the university’s Bloomberg School of Public Health, we work with city leaders and partners in the community to find solutions that can improve lives — and save them, in Baltimore and beyond. We oppose guns on campus not in the hackneyed stereotype of liberals scolding from the ivory tower but as a result of a searching examination of relevant research, as well as a common-sense assessment of reality. What the evidence to date shows — and what we hope state legislators across the nation who are pondering such measures will consider — is that campus-carry laws will invite tragedies on college campuses, not end them.