Two shootouts last week are part of a troubling phenomenon in which officer deaths have jumped to a level not seen in 29 years.
The shooting of four police officers, one of them fatally, near Miami on Thursday became another dark day in what is already a tough year for America's 800,000 police officers.
Coming only a few days after a shootout in Odessa, Texas, that killed three officers, the Miami incident became part of a troubling phenomenon for 2007: a spike in the number of police officers who died in the line of duty to a level not seen since 1978.
Of the 132 officers to die so far this year, 54 were shot. The number of shootings represents a 59 percent increase over the same period in 2006, according to the National Law Enforcement Officers Memorial Fund in Washington.
After years of watching these figures decline or hold steady, experts are not prepared to say whether this year's increase is a trend or an aberration.
Still, "the figures this year are nothing short of alarming," says Craig Floyd, chairman of the officers memorial fund.
Police offer several possible explanations for the high losses, including an uptick in violent crime around the country. Some experts suggest that community empathy for police, which rose after 9/11, may be waning now, especially in places where tensions exist between poor minority residents and police forces, or where transiency is relatively high, as in Miami or New Orleans.
The '07 trend line, while distressing, does not signal a danger level akin to that of the social upheaval of the 1960s and '70s, or of the "crack wars" of the late 1980s, experts say.