## Facts

- On 31 May 2010, Israeli forces intercepted a humanitarian flotilla bound for Gaza, including the Mavi Marmara and other vessels registered to States Parties to the Rome Statute (Comoros, Greece, and Cambodia).
- On 14 May 2013, Comoros referred the situation to the Prosecutor under Article 14 of the Rome Statute.
- On 6 November 2014, the Prosecutor concluded there was a reasonable basis to believe war crimes occurred (including wilful killing, wilfully causing serious injury, and outrages upon personal dignity) but decided not to open an investigation because potential cases were not sufficiently grave for admissibility.
- On 16 July 2015, Pre-Trial Chamber I (PTC) granted review under Article 53(3)(a) in part and requested the Prosecutor to reconsider the gravity analysis; a Prosecutor appeal was dismissed on admissibility grounds on 6 November 2015.
- On 30 November 2017, the Prosecutor again declined to open an investigation after reconsideration, maintaining the gravity assessment.
- On 15 November 2018, the PTC again found the Prosecutor’s reconsideration non-compliant with its directions and ordered a further reconsideration with specified instructions and a timeframe.
- The PTC denied leave to appeal on 18 January 2019; the Prosecutor nonetheless appealed to the Appeals Chamber challenging the PTC’s authority and the scope of its directions.
- On 2 September 2019, the Appeals Chamber issued judgment on the Prosecutor’s appeal against the 15 November 2018 PTC decision.

## Issues

1. What is the scope of a pre-trial chamber’s review, under Article 53(3)(a), of a Prosecutor’s Article 53(1) decision not to open an investigation following a State referral?
2. May a pre-trial chamber, when requesting reconsideration, issue detailed directions that constrain the Prosecutor’s analytical approach or predetermine the outcome on whether to proceed?
3. What constitutes adequate compliance with a reconsideration order, and what remedies are available if the chamber finds the Prosecutor’s reconsideration inadequate?

## Decision

- The Appeals Chamber confirmed that Article 53(3)(a) authorizes a pre-trial chamber to review a decision not to investigate and, where appropriate, to request reconsideration.
- The Appeals Chamber held that the chamber’s review is limited: it may identify legal and reasoning errors requiring reconsideration but may not substitute its own assessment for the Prosecutor’s or direct the Prosecutor to reach a particular conclusion.
- The Appeals Chamber found the PTC exceeded its powers to the extent it prescribed overly detailed instructions that effectively constrained the Prosecutor’s discretion and risked predetermining the reconsideration’s result.
- The Appeals Chamber set aside portions of the PTC decision and remitted the matter for further proceedings consistent with the Prosecutor’s independence and the chamber’s corrected understanding of Article 53(3)(a).
- The Appeals Chamber clarified that an earlier 2015 dismissal on admissibility grounds did not prevent the Appeals Chamber from addressing the merits of the scope of review in 2019.

## Legal Principles

- Article 53(3)(a) permits judicial review of a Prosecutor’s decision not to investigate after a State referral, but the chamber’s power is to request reconsideration, not to replace the Prosecutor’s decision.
- Judicial directions are binding to the extent they correct legal error and require reconsideration in good faith, but they must not dictate the substantive outcome or transform the chamber into a decision-maker on whether to proceed.
- A chamber may specify the nature of identified errors (e.g., omitted relevant factors or misapplied legal standards) and require a reasoned reconsideration; it may not compel the opening of an investigation or mandate how gravity is ultimately weighed.
- The Prosecutor retains “ultimate discretion,” within the Rome Statute’s bounds, in applying gravity and admissibility assessments under Articles 53(1) and 17(1)(d).

## Conclusion

The Appeals Chamber maintained a limited model of judicial control over non-investigation decisions: pre-trial chambers may require reconsideration to correct legal or reasoning errors, but they may not direct prosecutorial outcomes or prescribe an analysis so detailed that it effectively determines whether an investigation must be opened.


Situation on the Registered Vessels of the Union of the Comoros, the Hellenic Republic & the Kingdom of Cambodia, ICC-01/13 (Int’l Crim. Ct. App. Ch. 2019)