lineup指的是列队辨认。

一种刑事辨认程序。指将犯罪嫌疑人与其他具有相似形体特征的人排成一队列于受害人或证人之前，由其从中指认出犯罪人。列队辨认需符合一定的标准，且不能给予辨认人不适当的提示，这样，所得的辨认结果方为有效。有效的辨认结果如被作为证据在庭审中使用，辨认人应出庭作证。

A lineup is a relatively formalized procedure wherein a suspect, who is generally already in custody, is placed among a group of other persons whose general appearance resembles the suspect. The witness is then asked whether he can identify the perpetrator of the crime. The result is essentially a test of the reliability of the witness’s identification.

show-up指的是面对辨认。

审判前的一种辨认程序，由被害人或证人面对犯罪嫌疑人进行辨认。这种辨认与列队辨认〔lineup〕的目的是一样的，但后者更为正式。面对辨认通常是在犯罪发生后的短时间内或在列队辨认无法实施的情况下进行的。如果通过这种辨认而得出的证据将在法庭上使用，同样此种辨认应达到正当程序标准，被告人有权聘请律师。

A show-up usually occurs immediately or shortly after a crime has occurred. If law enforcement personnel see a person who they suspect is the perpetrator of a very recent crime, the officers may apprehend the suspect and bring him back to the scene of the crime and show him to witnesses, or the officers may take the suspect to a police station and bring the witnesses to the station. This method of identification of a criminal suspect is a legitimate tool of law enforcement and is encumbered by few judicial restraints.

以下为相关双语示例，供参考：

Show-ups are a valuable and practical tool in apprehending criminals. If a witness affirmatively identifies a suspect as the perpetrator of a crime, police can detain the suspect without delay to serve the interests of public safety. If a witness fails to identify the subject of a show-up as the perpetrator, the show-up will result in the quick release of the innocent suspect and allow police to redirect their efforts.

就逮捕罪犯而言，面对辨认是一个宝贵而又实用的工具。如果证人确定嫌疑人为犯罪行为人，警方客立即拘留嫌疑人，以维护公共安全。如果证人无法确认辨认的主体是犯罪行为人，那么面对辨认将导致无辜的嫌疑人被释放，并使得警方可以转变方向，重新开始寻找犯罪嫌疑人。

The lineup must be conducted by an independent administrator. However, in lieu of using an independent administrator, a law enforcement agency may conduct a photo lineup eyewitness identification procedure using an alternative method specified in subparagraph 1., subparagraph 2., or subparagraph 3. 

列队辨认必须由独立管理人士进行。但是，执法机构可能不会选择使用独立管理人士，而是采用第1款、第2款或第3款中规定的替代方法进行证人列队辨认照片指认程序。