Yes, they believe that LEOs are trained professional while non-LEOs are amateurs more likely to shoot themselves or other innocent bystanders — that’s what they think. History does not always support their beliefs. In fact, often times non-LEO citizens are more experienced and more capable with firearms. Think of all the non-LEO IPSC/Three Gun Competitors out there who are not policeman. These people surpass most SWAT members in shooting experience. Regardless what they think, they are causing people to die because of their policies.
In addition, weapons are an absolute necessity in a life or death situation. That's why LEOs carry them.
LEOs are not always at the scene, the potential victim always is. That's why they need to be armed.