Final answer:
Jennifer Thompson testified against Ronald Cotton in the case, influenced by suggestive police identification procedures.
Step-by-step explanation:
Based on the provided information, it is not specified which case the police reopened. However, if we assume it to be the case mentioned in the first paragraph where a witness testified against Ronald Cotton, the witness who testified against him was Jennifer Thompson. Jennifer initially had doubts but her certainty was influenced by suggestive police identification procedures. These procedures include stacking lineups to make the defendant stand out, telling the witness which person to identify, and confirming the witness's choices.