JDAI PRACTICE UPDATE
JUVENILE DETENTION RISK ASSESSMENT:
PROPER CALCULATION OF OVERRIDES and ACCEPTABLE OVERRIDE RATES
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What is the proper way to calculate your override rate?
What is an acceptable override rate for a detention risk assessment tool?
What steps might be considered if the override rate rises above acceptable limits?

1. Calculating the detain override rate
An override is a decision to detain or release a child in contravention of the risk score and
outcome recommended by the risk assessment instrument (RAI). “Detain overrides” (detentions
of low-scoring youth) may be chronic problems in some jurisdictions.
How are detention overrides calculated?


Overrides need to be measured by a common standard. In specific terms, the override
rate (percent) for any given period is properly calculated as the number of youth scoring
below the detention cutoff score who are detained (numerator) DIVIDED BY the total
number of minors in the same period having scores below the detention cutoff number
(denominator).
EXAMPLE - for a jurisdiction with a detention decision scale as follows:
0-8 points = release; 9-14 points = detention alternative; 15 or more points = detain.
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


Total number of minors screened for detention in the data period:
1,000
Total number scoring 15 or more points, or qualifying as mandatory
special detention cases that were detained regardless of score:
550
Total number scoring 9-14 points (detention alternative):
150
Total number scoring 0-8 points (release):
300
Total number of minors scoring 0-14 points who were detained:
200

DETAIN OVERRIDE RATE = 200 / 450 = 44 %
DETAIN OVERRIDE CALCULATION EXAMPLE

Detain override
rate formula
Youth eligible for release
or alternative (based on
RAI score) but detained
All youth eligible for
release or alternative
(based on RAI score)
Detain override rate

Total number of detained youth who were eligible
for release or an ATD based on their scores
÷ (divided by)
= Detain OR rate
Total number of youth who were eligible for
release or an ATD based on their scores
200
450
44%

 Calculating and controlling overrides of detention scores, page

2

Common error. Do not make the mistake of calculating the override rate using the number for
the entire screening sample (all referrals) as the denominator in the calculation as this produces
a false low override rate. The error would be exemplified, using the information above, as a
miscalculated detain override rate of 20% (200/1000) instead of the properly calculated detain
override rate of 44%.
How should other types of overrides be counted?


An “override up” from a score indicating release (8 or fewer points in the example above)
to a status of detention alternative is not a detain override and should not be included in
the calculation of your detain override rate. These overrides can be tracked separately;
the data will be useful in validating the risk instrument.



A “release override” occurs when a youth has a score above the detention cutoff score,
or is a mandatory/ special detention case, but is nevertheless released or referred to an
alternative. Release overrides are generally rare occurrences, but happen from time to
time for various reasons (e.g., minor is very young, minor has special problems that
cannot be addressed in the detention facility). These release overrides should be
tracked as a matter of routine monitoring of the RAI.

What is the difference between a “detain override” and an “aggravation” of the risk score that
results in secure detention?


Many detention risk instruments contain checklists of criteria that can be selected to
aggravate (raise) or mitigate (lower) the underlying risk score. These
aggravation/mitigation checklists apply collateral factors, supplementing the core offense
and case history factors. However, aggravation or mitigation of the underlying risk score
is not to be confused with an override of the score. Overrides, if applied, are applied to
the final score which includes net points in aggravation or mitigation.



In other words, a detention that occurs as a result of the aggravated score does not
count as a detain override. A detain override occurs only when the minor is detained
after scoring below the threshold value for secure custody.

2. Acceptable override rates
When detain overrides mount to high levels, the RAI becomes essentially dysfunctional and the
risk-screening process loses its integrity.
What is an appropriate override rate?


The National Council on Crime and Delinquency has proposed that detain overrides be
held to not more than 15 percent of youth who qualify for release (or for a non-detention
alternative), based on their risk scores.



A goal 15 to 20 percent (of children eligible for release) has been generally advanced by
JDAI technical assistance advisors as a target maximum override rate.



This 15-20 percent limit is advised as a maximum override rate, not as a normal or
permissible zone of routine operation. As noted in the JDAI practice guide, any detain
override rate “exceeding 25 percent should flash a warning signal that the screening
system needs immediate repairs”.

 Calculatina and control/inc overrides of detention scores, pace 3

 

Calculating and controlling overrides of detention scores, page

4

3. Addressing high detention override rates
High detain override rates may arise at any time. This may be due to problems with the
instrument itself, indicating a need to ensure that the override criteria on the instrument, as well
as the point values assigned to individual risk factors, are working as intended. High override
rates may also result from problems with the screening process, rather than problems with the
way the instrument has been designed. There may be a need to confront and change a specific
practice, such as routinely detaining technical probation violators with low scores or flagging too
many low-scoring youth as overrides on the basis that they are a “danger to self or others”.
Other frequent problems may include a lack of alternatives to secure detention, or a lack of
monitoring and enforcement of override criteria and limits.
What steps should be considered if the override rate rises above acceptable limits?




Gaining control over high detain override rates can be a daunting challenge. For a more
thorough review of this problem and recommended solutions, readers are referred to the
Juvenile Detention Risk Assessment: A Practice Guide available at
www.jdaihelpdesk.org.
Below is a troubleshooting chart taken from the Juvenile Detention Risk Assessment
Practice Guide, indicating possible causes for high override rates and suggested
solutions, with reference to the page in the text of the Practice Guide where these
problems and solutions are discussed.

PROBLEM: HIGH OVERRIDE RATES ARE LEADING TO THE SECURE DETENTION OF
MINORS WITH LOW RISK SCORES
Look for
CAUSES AND
SOLUTIONS RELATED
TO THE RAI

CAUSES AND
SOLUTIONS RELATED
TO THE SCREENING
PROCESS

Consider these strategies and solutions
Make sure there is a checklist of override reasons on the face of
the RAI
If there is an override checklist, make sure that the reasons
listed are not stated in broad and vague terms, inviting overuse.
Also, there may be too many override choices listed on the RAI.
Ensure that field tests track overrides of RAI scores to detect
and fix override problems early in the reform process.
Monitor overrides and reasons selected to identify ongoing
override problems and related adjustments.
Specific offenses or referral reasons may be omitted from the
lists of offense and delinquent history factors, so screeners are
using overrides to achieve detention in these cases. Adjust
descriptions or points for risk factors as appropriate.
Override procedures are not being followed by screeners.
Ensure that override reasons are checked in each case.
Ensure that supervisor approval is obtained for every override.
Examine release override policy and use; strive to balance
detain overrides with release overrides in appropriate cases.
Train screeners in override procedure and address problems or
attitudes of screeners related to compliance with RAI scoring
and decision-making procedures.
Set system override target limits. Review acceptable override
rates based on national best-practices.
Ensure that alternative-to-detention programs are available and
are utilized for minors with mid-range scores who may otherwise
be overridden into secure detention.

Practice
Guide page
number
22, 44
44
55
22, 44, 69
30
22, 44
18, 44
45, 55
44
22, 44
40