cinched the case = means that the jurors were convinced that the evidence presented was correct = it is a certainty.
combined with the claim that Padilla's purpose was humanitarian when various Muslim charities are accused of being mere fronts for terrorism,
Several Muslim charities are suspected of being fund-raising groups for terrorist groups; Padilla claimed to be working for a charity which was solely humanitarian in purpose.
The finding of his fingerprints on an application [form] together with his role with a suspect charity makes his defence position difficult.
Student or Learner