Of all the 73 officers killed, 31 died during an incident with a firearm -- up 24 percent from last year.
Eight of these deaths happened while the officer attempted to arrest a suspect, the report finds. Six officers have been killed while responding to disturbance calls. Three have died during an ambush.
Traffic deaths are the second leading cause of death among law enforcement officers, and the numbers are up slightly in the first half of 2018.
Twenty-seven officers have been killed in traffic-related calls. Eleven of those deaths were in multi-car crashes. Nine officers have been killed in single-car crashes, and seven officers have died after being struck outside of their cars.
Fifteen other officers have died of other causes -- a majority of which were job-related illnesses where an officer collapsed due to a heart attack.
Six first responders have died this year from illnesses related to the 9/11 attack.
One officer was beaten to death, and another drowned, according to the report.
Of the 73 officers who have died in the first half of 2018, 68 were male and 11 were female. Their average age was 39, with 11 years of service, the report states.
On average, each officer left behind two children.