circumstantial
adj
1 (of a description) giving full details (指描述)详细的.
2 (of evidence) consisting of details that strongly suggest sth but do not prove it (指证据)有充分细节却无法证实的
You can´t convict a man of a crime on circumstantial evidence alone. 不能只靠旁证就判定一个人有罪.