One of the affects that can occur from this is the officer unknowingly emotionally and physically distancing himself or herself from their loved ones. Some officers are known to have seen the faces of their children on the faces of dead children while on calls they have handled. Knowing the victim Though not common, there have been incidents where officers have responded to traffic fatalities or serious crimes, on arrival finding out the victim is their wife, children or another family member. More common, officers working the same beat who have made friends with people in the beat, such as a store clerk, may end up dealing with the same individual as a homicide victim. In some of the smaller or more rural agencies it's near impossible not to know a victim.
Depersonalization is easier in the larger cities, and a very helpful survival tool.
Lack of preparation Studies have shown that trauma that is encountered as a surprise has more ill affects than trauma that is anticipated. Being mentally prepared at all times is a major component of training all throughout an officer's career. So much time is spent making officers prepared for a shooting at all times, that you could easily become paranoid. Police work requires interaction with people on many levels, and no matter how prepared a person is there are always events it is impossible to prepare for. The nature of the job is that officers will occasionally drive or walk into a traumatic situation not knowing what is happening.