On Tuesday, Rivera led police to Mollie Tibbetts' body. She had been missing since July 18

Accused killer Cristhian Rivera left another girl fearing for her life after he tailed her in his car and tried to flirt with her - in a chilling echo of the Mollie Tibbetts murder.

Rivera pulled alongside the 17-year-old in his car as she walked through Brooklyn, Iowa, the same rural town where he would later be accused of following and abducting Mollie in strikingly similar fashion.

The girl's older sibling Bailey Gibson, 18, told DailyMail.com her younger sister was 'creeped' out by Rivera's advances as he told her she was pretty and tried to get her to stop.

'I know Cristhian from my sister. She thought he was a nice, well-spoken person. They hung out a few times but nothing really happened romantically,' she said.

'She told me that a little while ago he drove up to her while she was walking through Brooklyn. He told her she was really pretty and things like that.

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Bailey Gibson, 18, told DailyMail.com her younger sister was 'creeped' out by Rivera's advances as he told her she was pretty and tried to get her to stop

Rivera is shown leaving court on Wednesday in a prison jumpsuit. He appeared to be wearing a protective vest beneath it

'It was more flirty than sexual but my sister is very shy. She didn’t appreciate it. Even though she knew him a little she felt unsafe and didn't want to talk to him.

'In the end she was really creeped-out by his behavior. She had to keep telling him she wasn't interested.'

Gibson said Rivera eventually left her sister alone and she didn't think anything more about it until she read how the accused killer had allegedly followed Mollie in his black Chevy Malibu while she was out jogging on July 18.

Mexican national Rivera, who authorities say is an illegal immigrant and whose employer say used a fake name and someone else’s ID and Social Security number to get a job, appeared in court Wednesday charged with Mollie’s murder and was held on $5million bond.

Rivera said nothing other than answering yes and no to his interpreter when prompted.

If convicted, Rivera could face deportation or life imprisonment without parole. The judge on Thursday said he may also have to register as a sex offender.

It is not yet clear how Mollie died or whether she was sexually assaulted thought Rivera was told during his court appearance Tuesday that he would be placed on the sex offender registry for life if convicted of murder

Rivera's three-year-old daughter was in the public gallery along with her 25-year-old mother

Rivera's girlfriend Iris Monarrez is seen in a yearbook photos above. She was dating Rivera throughout her years at the school

Rivera, who has been in the US illegally for between four and seven years, admits he followed Mollie and got mad when she tried calling the police - but says he 'blacked out' and can't remember attacking her.

He said he found her in the trunk of his car with blood coming from her head and hid the 20-year-old's body in a field.

Rivera was identified by surveillance footage obtained in the last couple of weeks that showed him following the student in his car and Mollie running ahead of him.

It is not yet clear how Mollie died or whether she was sexually assaulted thought Rivera was told during his court appearance Tuesday that he would be placed on the sex offender registry for life if convicted of murder.

'It all clicked when we heard the news. It's so scary to think he did something similar with my sister,' added Bailey, who asked that her sibling not be named.

Monarrez (is seen above outside court today) is friends on Facebook with Mollie Tibbetts and her brothers Scott and Jake

Rivera's girlfriend Iris Monarrez was also in court Tuesday to support him, clutching the child they had together in 2015.

Monarrez is friends on Facebook with Mollie Tibbetts and her brothers Scott and Jake.

DailyMail.com can reveal she attended the same school, Brooklyn, Guernsey, and Malcom High, as Mollie but was in the year above.

She was dating Rivera throughout her years at the school, raising the possibility that Rivera knew of Mollie years before he abducted and allegedly killed her.

Iris Monarrez was on the cheerleading squad and is seen in this yearbook photo circled above

Monarrez declined to speak to reporters as she left court Tuesday. She is seen above in yearbook photos

Mollie and Iris actually appear on opposite sides of the same page in the 2015-16 edition of the ‘Make It Count’ yearbook. Mollie is seen circled on the left and Iris right hand page

'Iris was very quiet, she kept to her friends. From what I can see she was a really nice person, shy but kind. She didn’t stick out,' added Bailey.

'I'm sure she's as shocked as we are.'

Brooklyn, Guernsey, and Malcom High School only has around 250 pupils making it likely that Mollie and Monarrez knew one another.

Monarrez graduated in 2016, a year ahead of Mollie, and was on the school’s cheerleader squad.

Mollie, meanwhile, ran track and competed on the school debate team.

The pair actually appear on opposite sides of the same page in the 2015-16 edition of the ‘Make It Count’ yearbook.

Monarrez declined to speak to reporters as she left court Tuesday.

'Iris was very quiet, she kept to her friends. From what I can see she was a really nice person, shy but kind. She didn’t stick out,' added Bailey (pictured)

Brooklyn, Guernsey, and Malcom High School only has around 250 pupils making it likely that Mollie and Monarrez knew one another. The school is seen above