The man accused of pursuing and killing 20-year-old Mollie Tibbetts had worked four years at an Iowa dairy farm based on false identification, his employer said Wednesday.

“What we learned in the last 24 hours is that our employee was not who he said he was,” said Dane Lang, the co-owner and manager of Yarrabee Farms.

That revelation came about an hour after the employee, Cristhian Bahena Rivera, was arraigned on a first-degree murder charge for the killing of Tibbetts. His bond was set at $5 million and his next court hearing is scheduled for August 31.