Sgt. Patrick O'Rourke of West Bloomfield Memorialized in DC

This week, family members and representatives from the West Bloomfield Police Department to participate in ceremonies honoring Sgt. Patrick O'Rourke, and others killed in the line of duty across the U.S.

O'Rourke was shot and killed in September by a man who barricaded himself in his West Bloomfield home after a domestic dispute.

From postal inspectors to small-town sheriffs, Congress has dedicated the week of May 15 each year to honoring America's law enforcement officers, especially those killed in the line of duty.

While the number of officers killed in the line of duty has fallen since the 1970s (see our graphic, above), more officers have been killed so far in 2013 than the same time last year, according to a report by the Law Enforcement Officers Memorial Fund, released on Monday.

The FBI also released a report on Monday, which showed officer fatalities declined in 2012 compared to 2011. The FBI report said 47 officers were killed by criminals and 45 officers were killed accidentally while on duty last year, a total of 92 officers. The National Law Enforcement Officers Memorial Fund, which counts line-of-duty deaths differently, puts the total number at 127.

The FBI report found that 43 of the 47 officers killed feloniously were shot, while most who died accidentally were involved in automobile accidents.

"It is not how these officers died that made them heroes," a message engraved on the National Law Enforcement Officers Memorial in Washington, D.C. says. "It is how they lived."

Police dogs were also honored as "K-9" officers at ceremonies around the country. Eighteen dogs died in the line of duty last year, and 7 have given their lives this year, according to the Office Down Memorial Page.