I told the specialist about the foregoing and said that I was willing to testify under oath .

我向该专家讲述了前面提到的那件事并表示愿意 宣誓 作证。

He testify under oath that he have not is at the scene of the crime .

他 宣誓称自己当时不在犯罪现场。

Will you testify under oath ?

你可以 宣誓 证实吗？