| Item | Count | Percent |
| Total | 16 | 100.0 |
| Weak or insufficient admissible evidence | 8 | 50.0 |
| No federal offense evident | 2 | 12.5 |
| Suspect being prosecuted on other charges (e.g., UFAPs) | 2 | 12.5 |
| Lack of evidence of criminal intent | 1 | 6.3 |
| Lack of investigative or prosecutive resources | 1 | 6.3 |
| Suspect to be prosecuted by other authorities | 1 | 6.3 |
| All other | 1 | 6.3 |