Legal status

[Supplementary Tables M1 and X1]

There are known discrepancies between legal status populations determined using cellWise data and the live system data in other published sources. These discrepancies arise from an undercount of remand status individuals due to the classification heirarchy applied in the construction of the cellWise data. Information on legal status should be interpreted alongside ‘live’ sources of data. These differences are laid out in the Legal status discrepancies section below.

This year we have attempted to reconcile the apparent shortfall in remand estimates from cellWise by overlaying and matching live daily data. The results of this exercise are provided as official statistics in development in  the section Statistics in development: Reconciliation of legal status discrepancies.

cellWise estimate

The overall (average daily) prison population increased by 4.5% between 2023-24 and 2024-25. Figure 7 breaks the average daily population down by legal status[i] category, showing that growth was driven primarily by increases in the sentenced population. The average daily sentenced population increased by 350 (+5.8%) to 6,367 in 2024-25.

Over the same period, the untried population decreased by 34 to 1,446, while the convicted awaiting sentence (CAS) population increased by 35 to 351. Overall the remand population remains at the same level as the previous two years (1,797).

Figure 7: Population growth in 2023-24 and 2024-25 was the result of a growing sentenced population. The overall remand population has remained broadly stable in the past three years

Average daily populations by legal status, 2009-10 to 2024-25

Figure 8 and Figure 9 provide the monthly and quarterly remand and sentenced populations since January 2020. After an initial sharp decrease, the remand population grew rapidly to September 2020, levelling off thereafter for the remainder of 2020-21 at a higher level than pre-pandemic. While there have been some fluctuations, the remand population has remained at a higher level since September 2020.

Figure 8: The remand population has remained broadly stable at a higher level since autumn 2020

Monthly and quarterly average remand prison populations, January 2020 through March 2025

The sentenced population fell substantially and rapidly between April and July 2020 (Figure 9). It was then broadly stable (between 5,500 and 5,700) at a level considerably lower than during the pre-pandemic period. From early 2023, the sentenced population began to grow at a considerable rate. Measures taken to manage prison population levels have had an impact (see Monthly and quarterly variations): in June and July 2024 there was a sharp population reduction and there was a reduced population in March 2025. Nevertheless there has been substantial overall growth in the sentenced population.

Figure 9: Substantial overall growth in the average sentenced population

Monthly and quarterly average sentenced prison populations, January 2020 through March 2025

Legal status discrepancies

The following discrepancies arise when comparing the cellWise and SPS aggregate estimates of legal status populations from 2020-21 onwards:

• A growing underestimate of the average daily Untried population from 10% (151) in 2020-21, to 20% (371) in 2024-25
• A growing underestimate in the average daily Convicted Awaiting Sentence population, which goes from 2 (1%) in 2020-21 to 34 (9%) in 2024-25
• A growing overestimate of the average daily Sentenced population, from 108 (2%) in 2020-21 to around 356 (6%) in 2024-25

These differences over time are illustrated in Figure 10:

Figure 10: Comparison of sources of population estimates by legal status

Comparing SPS aggregated population estimates by legal status with those produced by cellWise – the data source for this publication, 2014-15 to 2024-25

Statistics in development: Reconciliation of legal status discrepancies

In this section we discuss developing efforts to reconcile the cellWise estimate of remand populations with other available data. At present this cannot be extended to other analysis, like offences and sentences, due to the complexities of those changing statuses.

Due to the lack of information retained on PR2 about the end point of custodial sentences, prisoners whose sentence/s expire but who remain in prison on a remand warrant/s continue to be counted as sentenced for their on-going Occupancy Period[ii]. This aspect of the data construction is explained in further detail in the accompanying technical manual[iii]. We term these prisoner movements as “retrograde transitions”, i.e. a transition from sentenced to remand.

A subset of information is drawn down from the SPS Prisoner Records System (PR2) each day just after midnight by Justice Analysis and Strategy (JAS) analysts. This collection of snapshots was started on the 25th March 2020[iv].

From these daily snapshots we can detect retrograde transitions by comparing an individual’s legal status on consecutive days. There were 656 retrograde transitions (from sentenced to remand) in the course of 2020-21, growing to 1,619 in 2024-25. In addition there were 125 transitions from CAS to Untried in 2020-21, growing to 265 in 2024-25. Such transitions cannot be detected in the cellWise data construction.

We have used the spsMI collection to determine the effect of accounting for retrograde legal status transitions and missing legal statuses in the cellWise data on the estimates of average daily remand population. The dataset combining daily snapshots and the cellWise data is termed “snapWise” in Table 1. Its construction is detailed in the SPS Daily MI Collection Technical Manual[v].

Figure 11: snapWise Correction Effect

The full remand deficit shown in Figure 11 is recovered when we account for retrograde legal status transitions (i.e. from sentenced to remand statuses). A small amount of additional population is provided by accounting for the periods of unknown legal status in cellWise, meaning the snapWise corrected remand population estimate slightly exceeds the deficit from cellWise data alone.

Accounting for retrograde transitions, the remand population rises from the 1,797 cellWise estimate to 2,210, slightly exceeding the full aggregate remand population produced by SPS. This increases the proportion judged to be on remand in 2024-25 from 21.9% to 26.9%.

Table 1: Remand Deficit Correction

Operational and analyst colleagues in SPS, were asked why retrograde transitions were increasing between 2020-21 and 2024-25. Several possible reasons were suggested, however it has not been possible to quantify their relative effects:

• Increased Journey Times through court[vi], meaning outstanding remand warrants are not disposed until after a previous sentence is served.
• Warrants being served by Police on people in custody, instead of being delayed until they are released (which would lead to a separate occupancy period).
• In-custody offending, and its increasing detection through new technologies like the Rapiscan Itemiser (for uncovering drugs possession)

All following sections revert to the cellWise estimate of Legal Status, as further development is required to extend this integrated analysis.