There would appear to be a huge dichotomy between the fact that a police officer has the right to use lethal force and the fact that according to http://www.deathpenaltyinfo.org, as of 2012 the average length of time between sentencing and execution for prisoners convicted of capital punishment is at 190 months. This essentially means that a police officer in perhaps less than 19 minutes can take away the life of a human being, whereas if brought to a court of justice, it would take on average 190 months, if the perpetrator was convicted and sentenced to capital punishment which is of itself, currently legal in just 32 of our 50 states.
According to usatoday.com, there are no complete statistics that tell us exactly how many people are killed by police forces throughout the United States, however, usatoday.com states, "nearly two times a week in the United States, a white police officer killed a black person during a seven-year period ending in 2012, according to the most recent accounts of justifiable homicide reported to the FBI." While, regrettably there are times where lethal force is necessary, the prevailing reason why lethal force is exercised as often as it is in America, is because the weapons that the police use in so many communities are extremely effective in the taking away of life. It should not have to be that way.
The most significant problem that our police forces have today is the massive amount of weapons and firepower that they have in their hands or in their vehicles or available as backup. It doesn't take a genius to determine that the more firepower that you provide to a given police department, the more firepower that will eventually be utilized or deployed, especially if the prevailing mindset is to go into a situation with overwhelming force. I sincerely doubt that there is a single criminal alive today who in his right mind believes that he can out-think, out-gun, or out-maneuver an experienced police force. That being the case, it doesn't make a whole lot of sense for police to escalate a dangerous or a volatile situation to which there does not appear to be any real justifiable reason to begin the firing of their lethal weapons. Police forces often have the manpower, the sophistication, the technology, and the experience to deal with a multitude of situations in which time is often on their side and sudden swiftness of lethal force is not required, nor necessitated.
The usage of alternatives to lethal weapons which are not typically lethal such as TASERs, batons, rubber bullets, pepper spray, strobes of light/noise and other devices should be a first consideration within any respectable police force. The objective, except in situations of extreme urgency, should be to neutralize the target so that the person(s) can be brought to justice and not to terminate their life. The killing of another human being by a police officer cannot be undone, it cannot be corrected, it cannot be amended, and while I certainly admit there are times when lethal force is necessary and right, in order to reduce those situations, you must first reduce the usage of the very weapons themselves which take away human life.