Download force-month files from the data.police.uk archive

Fetches the street, outcomes and stop-and-search CSV files for chosen months and forces from one or more archive snapshots, without downloading the whole zip: the zip's table of contents is read with an HTTP byte-range request and each wanted file is then fetched by range and inflated locally. Files already present in the cache with a matching checksum are skipped. Each fetched file is recorded with its CRC32 from the archive, a SHA-256 of its content and the time of download, which is what the panel contract reports as provenance.

Usage

lamp_archive_download(
  archives = "latest",
  months = NULL,
  forces = NULL,
  file_types = c("street", "outcomes", "stop-and-search"),
  dir = lamp_cache_dir(),
  index = NULL,
  relist = FALSE
)

Arguments

archives

Archive identifiers such as c("2026-06", "2026-07"), or "latest" (the default) for the newest snapshot in lamp_archive_index().

months

Months to fetch as "YYYY-MM" strings or Dates; NULL for every month in the archive.

forces

police.uk force identifiers such as "west-yorkshire"; NULL for every force. See lamp_forces().

file_types

Which of "street", "outcomes" and "stop-and-search" to fetch.

dir

Cache directory; see lamp_cache_dir().

index

An archive index from lamp_archive_index(), to avoid fetching it again.

relist

Read the archive's table of contents again even if it has been listed before.

Value

A lamp_snapshot (see lamp_archive_snapshot()) for dir, invisibly.

See also

Other ingest: lamp_archive_index(), lamp_archive_register(), lamp_archive_snapshot(), lamp_list_versions(), lamp_lsoa_vintage(), lamp_read_crime(), lamp_read_outcomes(), lamp_read_stop_counts(), lamp_s60_legislation(), lamp_select_version(), lamp_version_diff()

Examples

if (FALSE) {
# Requires network access; fetches about 20 MB
snap <- lamp_archive_download(
  archives = "latest", months = c("2026-05", "2026-06", "2026-07"),
  forces = c("west-yorkshire", "dyfed-powys")
)
snap
}