There are jobs that are more dangerous than police work, but law enforcement has something that sets it apart from other professions.
''Generally, when a police officer dies, someone was trying to kill him,'' said Alexander Weiss, an associate professor of criminal justice at Indiana University. ''There are jobs with more absolute risk, but not of that type.''
Police officers are most likely to be killed in January and December, according to the National Law Enforcement Officers Memorial Fund. And during the past 10 years more officers have been killed on Fridays than another other day.
Those probabilities played out when two Cincinnati officers were shot fatally . . . on the first Friday of December.
Terrible as that is, police deaths from all causes generally have declined for years across the nation.
In 1996, there were about 116 deaths - the lowest since 1959, according to the memorial fund.
The decline in police deaths began in the 1980s, when more officers began wearing protective vests, Mr. Weiss said. ''Before the 1980s it was rare to see an officer in body armor,'' he said. ''Now it's common.
A Bureau of Labor Statistics (BLS) analysis of 1995 deaths among every 100,000 workers found police work was less dangerous than truck driving, farming, being a construction laborer, pilot, taxi driver, timber cutter, roofer, commercial fisherman, metal worker or electric power installer or repairer.
But when a police officer dies while on the job, it touches a community in a way most occupations can't for important reasons, Mr. Weiss noted.
''There's a notion the police serve a vital function in maintaining order,'' he said. ''And if the police are vulnerable, it make the whole community feel vulnerable.''
Finding trends in police killings - such as determining whether they're more likely to happen one day vs. another or finding why one month has more than another - is difficult because they are so rare, said Mitch Chamlin, an associate professor of criminal justice at the University Cincinnati.
''I'm not sure the December-January thing makes much sense, and Friday is the most common day probably because of opportunity,'' he said. ''Any time you study rare events, it's difficult to find a pattern. Trying to make sense of it in a statistical sense can be difficult.''
Even with the figures available there are problems.
For instance, FBI Uniform Crime Reports said 74 officers were ''feloniously slain in line of duty in 1995.''
However, BLS said among 174 police officers who died on duty in 1995, 47 were homicide victims. The second most common cause of death was traffic accidents.
Similarly, it was not clear whether fatal gunshots in some statistics included suicides.
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