The girlfriend of a man accused of killing a Chinese graduate student wore a wire for two weeks to help police catch him, it has been revealed.
克里斯滕森被控告杀害中国研究生章莹颖，据报道，其女友在携带监听设备两周后协助警方抓捕了克里斯滕森。
Brendt Christensen, 28, is accused of kidnapping and killing scholar Yingying Zhang after allegedly kidnapping her on June 9 last year.
去年6月9日，28岁的布伦特·克里斯滕森绑架了章莹颖，被控告绑架和故意杀人罪。
She vanished after telling friends she was going to sign an apartment lease near the University of Illinois where she was studying.
章莹颖就读于伊利诺伊大学，消失前刚告诉朋友她要去学校附近签订租房合同。
For weeks, police suspected Christensen but had no evidence to arrest him.
警方连续数周将怀疑目标锁定克里斯滕森，只是苦于没有证据。
In court on Tuesday, his lawyers however revealed that his girlfriend, who he was filmed attending a vigil to help find Zhang after she went missing, wore a wire to record hours of their conversations in the weeks which followed her disappearance.
周二，克里斯滕森的律师团在法庭上表示，有监控记录了克里斯滕森和女友一同守过夜，协助寻找当事人，并公开了克里斯滕森和女友在章莹颖消失后几周数小时的谈话录音。
Among the conversations was one in which Christensen allegedly confessed to the killing and described how Zhang, 26, fought back when he attacked her.
在录音中，克里斯滕森承认杀害了章莹颖，并详细叙述了26岁的受害者在受到攻击后进行了抵抗。
He is also said to have described his 'perfect victim' by pointing them out in the crowd at the vigil where he was filmed walking hand in hand with the woman.
克里斯滕森还表示，守夜的时候他在人群中挑出了“理想受害者”，也是在守夜中，有监控拍到他和女友手牵着手走在路上。
Christensen's lawyers did not reveal how the FBI contacted his girlfriend.
克里斯滕森的律师没有详细说过美国联邦调查局联络他女朋友的方式。
They pleaded with a judge to not allow the taped conversations into evidence at his trial, claiming the girlfriend was pressured into wearing the wire because she feared charges herself.
但是律师团请求法官不要将录音作为审判时的证据，表示其女友是迫于压力才协助监听，并不想引火上身。
On one occasion, she was apparently so nervous about wearing it in front of him that she fainted, his lawyers claimed.
律师团表示，克里斯滕森的女友曾因在嫌疑人面前戴着监听设备过于紧张，以致昏倒。
Christensen also allegedly tried to lure another student into his car on the day Zhang went missing.
据称，章莹颖消失当天，克里斯滕森还试图诱骗另一位学生上车。
That student told investigators that he pretended he was a cop to try to get her into his vehicle. She identified him through photographs shown to her by police.
那位学生告诉调查人员，当天克里斯滕森假装是警察，诱骗她上车，警方向她出示照片后，她表示此人就是克里斯滕森。
Zhang's body has never been found. Her death shocked her relatives in China who believed she would be safe in the small campus town where she spent most of her time.
警方尚未发现章莹颖的尸体。章的家人难以相信她已死亡，坚信章仍在某个小镇上好好活着。
Christensen is also married. It is not clear if he and his wife, who has not been identified, are estranged.
克里斯滕森已婚，妻子身份尚不明确，两人是否还有联系仍有待调查。
His lawyers are asking for his trial to be moved to Chicago, claiming the case was so high profile that he has no chance of a fair trial.
克里斯滕森律师团要求在芝加哥进行审批，说这件案子声势太大，会影响审判的公平性。
Zhang's family traveled to the US from her native China after she disappeared.
章消失后，其家人从中国前往美国。
Her grieving father was still in the country in November last year after authorities said she was presumed dead.
去年11月，官方宣布章死亡后，其父仍留在美国，悲痛欲绝。
He walked the route to her apartment from campus every day, he said, because it gave him comfort.
每天，章父都要从学校走到章莹颖住处，他说这样心里舒服些。
At the time, her mother said: 'We don't know where she is, and I don't know how to spend the rest of my life without my daughter.
章的母亲说：“我们不知道莹颖在哪，我也不知道没了女儿往后要怎么活。”
'I can't really sleep well at night. I often dream of my daughter, and she's right there with me.
“晚上睡不好，老是梦见我们家莹颖和我在一块儿。”
'I want to ask the mother of the suspect, please talk to her son and ask him what he did to my daughter. Where is she now? I want to know the answer.'
“我想拜托嫌疑人的母亲，能不能和她儿子聊聊，到底把我闺女怎么了，我闺女现在在哪？我就想知道她在哪儿。”
The FBI previously said they had obtained 'audio surveillance' from the vigil which Christensen attended.
联邦调查局此前表示他们已经拿到了克里斯滕森守夜时的“录音记录”。
They did not disclose that it was recorded by his girlfriend.
但调查局并未透露记录来自克里斯滕森的女友。
He is charged with kidnapping resulting in death, which carries the potential of the death penalty on conviction.
克里斯滕森目前被指控绑架导致受害者死亡，可能会被判处死刑。
