Mollie Tibbetts' suspected murderer behaved normally at work in month after her death, manager says

Cristhian Bahena Rivera, charged with murdering Iowa college student Mollie Tibbetts, didn't show any signs of unusual behavior at work in the month following her disappearance and death, his manager told CBS News.

Tibbetts disappeared after a jog on the evening of July 18, and Rivera led police to her body and was charged with her murder more than a month later.

Rivera's manager, Dane Lang, said "nobody saw a difference" in Rivera at Yarrabee Farms where he worked, and that his co-workers were shocked to find out he was the suspected killer.

"Our employee is not who he said he was," Lang said in a news conference. "This was shocking to us."

Immigration status debate continues

Even though Rivera's attorney insisted in court earlier this week that his client was in the U.S. and working legally, on Wednesday he acknowledged that Rivera had been working and getting paid under a different name, and that he didn't know Rivera's immigration status.

That, however, won't stop the attorney, Allan Richards, from continuing to argue that Rivera was in the U.S. legally.

"He showed up every day and he did this job," Richards said. "He was patted on his back. They turned a blind eye to the reality of the documentation."

Immigration and Customs Enforcement has issued a detainer on Rivera, and a hearing on his immigration status is still pending.

Backlash against the farm

Lang said his farm has received dozens of calls since Rivera's arrest, many of them including threats to his property, and even his dog. Lang called it a "scary situation."

The story of how Rivera came to work for Yarrabee Farms despite a lack of legal immigration status has changed throughout this situation.

First, a statement from the farm said they had run Rivera through the government's E-Verify system, and that he had passed. They later admitted they hadn't used that system to check Rivera.

Now, the report is that Rivera presented a government-issued ID and matching Social Security card under a different name, and his background was only checked through the Social Security Administration's verification system, which is different from the E-Verify check.

"What we learned in the last 24 hours is that our employee was not who he said he was," a Yarrabee Farms statement read. "And just within the last four hours, we have come to learn the SSN verification service is not the same as E-Verify. They are not the same systems and we apologize for any confusion this caused with our earlier statements."