This topic/question is...expansive. I will say however that police tactics (when emphasis is placed on training and development) tend to be amongst the most effective one will find anywhere. Law enforcement tactics develop directly as a consequence of life and death circumstances law enforcement personnel face on a daily basis.
One can look at the example of William Fairbairn (1885–1960) as an illustration of this. He was a decorated British officer who worked with the Shanghai police and drew from his combat experience and training, as well as his martial arts training and experiences on the streets of Shanghai to develop defensive tactics that are still relevant to this day.
With the increasing militarization of law enforcement agencies here and abroad (more powerful and varied types of weaponry, increased emphasis on military-type, small unit tactics, increased intelligence presence), as well as the role of military forces worldwide taking on more of an enforcement role (particularly with an emphasis on urban combat tactics, crowd control, house searches, etc) the average police officer is far more tactically savvy than he/she would have been 10-15 years ago.
The partial blurriness of the line between what defines military and police training has benefitted both areas. One huge benefit of this is the increased emphasis on tactical awareness is a higher level of training for the individual operator, particularly regarding unarmed tactics. In the tradition of (and largely inspired by) innovators like Mr. Fairbairn, more operators than ever before are training in some form of martial arts or practical self-defense system. If one takes an informal survey amongst police, security and military personnel, one will find most have and maintain some degree or level of training in unarmed combat. Whether it's karate, kenpo, jujitsu, boxing, muay thai, wrestling, judo, Filipino martial arts (kali/arnis/escrima), tae kwon do, or any of a myriad of other disciplines, or even a combination of two or more of such, operators are understanding the need to master the basic dynamic of physical confrontation.
The benefit of hands-on personnel driving the increased popularity of the various martial arts, self-defense and fighting disciplines is that the approach to these overall is one of practicality, coupled with the traditional discipline, conditioning, artistic aesthetics and forms inherent to each in mind.