The annual report from the nonprofit National Law Enforcement Officers Memorial Fund also found that deaths in the line of duty generally fell by 8 percent and were the fewest since 1959.
According to the report, 111 federal, state, local, tribal and territorial officers were killed in the line of duty nationwide this past year, compared to 121 in 2012.
Forty-six officers were killed in traffic related accidents, and 33 were killed by firearms.
The number of firearms deaths fell 33 percent in 2013 and was the lowest since 1887.
The report credits an increased culture of safety among law-enforcement agencies, including increased use of bulletproof vests, that followed a spike in law-enforcement deaths in 2011.
Since 2011, officer fatalities across all categories have decreased by 34 percent, and firearms deaths have dropped by 54 percent.
Fourteen officers died from heart attacks that occurred while performing their duties.
The report found that Texas and California had the highest number of fatalities, with 13 and 10, respectively.