Now, I'm only using Glock as an example here. Any mechanical device can, and will, break. Some guns are just easier to fix than others. All manufacturers of quality police firearms have established armorer courses and recommended maintenance/inspection schedules. An agency ignores them at their peril. If an agency firearm fails to function properly when it is really needed, any subsequent investigation is going to look at the maintenance records for that particular arm. If none are available, the agency has placed itself in a very difficult position. Agencies that put a lot of effort into the selection of a particular weapon and then don't keep up with the maintenance of it, can find themselves with civil liability issues that will stress the budget far more than the cost of having certified armorers support an effective maintenance program. And the agencies owe it to the people who rely on the guns to make sure they are ready when the need arises.
On the other hand, individual officers must do their part. Know the recommended cleaning and inspection procedures--and follow them! It is, after all, your life. Know what to look for when doing an operational and safety check. And be sure to report any problems or ask any questions. But keeping the gun clean and safe isn't the only thing. Don't do your own gunsmithing. Play with your own guns, if you must, but don't tinker with the department hardware. The guns need to remain "in spec," both to ensure reliability and prevent liability issues. Some people think they can improve on the years of design and testing that manufacturers have put into their products. If the gun really is a problem for you, then let your department work that out. That's their responsibility. But home gunsmithing can come back and bite everyone in the behind, even if it is done with the best of intentions. A good armorer should be able to recommend solutions. And if not, then maybe a different gun is in order. I still run across folks who will tamper with a perfectly good gun rather than change to another type or brand that would fit the bill, without the risk of reliability or liability issues. It just isn't worth it. In fact, many of the malfunctions I see on the range are the result of someone trying to "improve" something on their gun, but not understanding how the whole thing works as a complete machine. They are, after all, machines. The parts are designed to work together, and altering one part can often have unintended effects on other parts. I recommend that folks spend their energy learning how their guns work and how to keep them working. This can be accomplished in less than an hour. It is time well spent. Problems with feeding, extraction/ejection, slide cycling and misfires can all come from not knowing how the gun is supposed to operate. Don't forget: reliability is still the number one attribute of a personal protection firearm.
Maintaining department firearms is a partnership between the officer and the agency. Police weapons are, after all, safety/rescue equipment. They will perform safely and reliably if everyone works together to keep them ready for duty. If you are into the mechanical aspects of the gun, maybe your department is looking for armorer candidates. If you are the department decision-maker, check with the manufacturer of your weapons to make sure you have established a recommended program for inspecting and maintaining your firearms. The investment in such a program is well worth the time, money and peace of mind--for everyone.