Police officers in the United States have shot and killed at least 500 people so far in 2015, according to a Washington Post analysis.

The 500th gun death at the hands of police officers came Thursday night in Boulder Creek, Calif., after officers were dispatched to a home on reports of a family fight. Police officials told local media that when they arrived, they encountered a man with two firearms whom they shot and killed.

It was one of four fatal police shootings that occurred on Thursday — the others were in Chicago, Phoenix and Parowan, Utah.

The 500th fatal police shooting comes amid a particularly deadly stretch — at least two people have been shot and killed by police every single day so far this month. At least 31 people were shot and killed by police officers during the first week of July, making it the deadliest such week of the year so far. On Tuesday, officers across the country shot and killed eight people, the most police shootings that have occurred on any single day in 2015.

The number of people shot and killed so far this year tracked by The Post easily exceeds the figures reported by the FBI for any single year since 1976. The federal data, which officials acknowledge is incomplete, relies on voluntary reporting from just a sliver of the nation’s  more than 13,000 state and local police departments. While the FBI has never recorded more than 460 fatal police shootings in an entire year, The Post identified 463 such shootings in just the first six months of 2015.

Due in part to this inadequate data, The Washington Post is tracking every fatal shooting by a police officer in the line of duty in 2015. The stories of each person shot and killed are being collected in a database that includes details about each episode. (Read more about the methodology here.)

Steven Rich and Jennifer Jenkins contributed to this report.