As current and former New Hampshire police chiefs, we've been following the national debate on how to prevent mass shootings. All of us in law enforcement want to stop violence and keep our cities and towns safe. And we're glad that Sen. Kelly Ayotte is at the table, putting her experience as a prosecutor and attorney general to good use...We know Kelly because we worked with her during her long career at the Attorney General's office, where she rose from a prosecutor, to chief of the homicide unit, to deputy attorney general, and then to the position of top law enforcement officer. She is someone who continues to be totally committed to law enforcement. And we know that when it comes to public safety and preventing violence, no one works harder than Kelly Ayotte. Based on the strength of that record, she was overwhelmingly elected to the Senate with the strong support of New Hampshire's law enforcement community...Our hearts certainly go out to Rep. Gabriel Giffords for the horrible tragedy she was forced to endure. But an op-ed that she wrote didn't mention that a group she backs has been running ads falsely attacking Kelly Ayotte. Contrary to what these ads say, Sen. Ayotte did in fact vote in support of legislation to improve the nation's background check system for those who attempt to buy firearms...It's unfortunate to see out-of-state groups throw mud in this important debate. Having worked directly with Kelly, we know that she's fully committed to prosecuting criminals. When she was attorney general, Kelly worked hand in glove with law enforcement officials, listened to what we had to say and sought our input on public safety issues. Because of her personal efforts, she remains extraordinarily well-respected by New Hampshire's law enforcement community...One of the main reasons she is held in such high regard is because she is someone who takes time to look at both sides of an issue. She does her homework, and she asks tough questions. Kelly has always been focused on finding pragmatic solutions...In the current debate, we've been glad to see her focus on improving the nation's mental health delivery system. We all know that serious mental illness is a common thread between these mass shootings. As current and former chiefs, all of our departments have dealt with the issue of mental health, including identifying the warning signs and trying to help those in crisis get the help they need. This problem is very real, and we're glad to see that Sen. Ayotte has been working to address this important issue...We also have appreciated her efforts to ensure that the gun laws we have now are enforced. As law enforcement officers, one of the most frustrating things is to see law-breakers get away with their crimes. Kelly shares that commitment, and she voted for a bill that would make sure prosecutors have the resources to prosecute those who illegally try to buy firearms...Finally, as experienced law enforcement officers, we know that most criminals get their guns by stealing them or getting others to buy guns for them. The legislation Kelly worked on increased criminal penalties for straw purchases and gun trafficking...Preventing violence and crime requires getting the right policies in place. As Congress debates proposals, we're glad that Kelly Ayotte is at the table, using her background in law enforcement to write practical laws that will actually address this very complex problem...Dick Crate is chief of police of Enfield; Russ Lary is the retired chief of police of Grantham; Christopher Connelly is the retired chief of police of Dunbarton; and John Tholl is the retired chief of police of Dalton.