An Iowa professor has been charged for allegedly gagging and binding her husband to a chair with rope for hours before his death, authorities said on Wednesday evening.

Gowun Park, a 41-year-old assistant economics professor at Simpson College, was charged with first-degree murder and first-degree kidnapping in the death of her 41-year-old husband, Sung Nam, on Saturday, West Des Moines police told The Daily Beast.

“Ms. Park’s actions and in-actions were directly responsible for Mr. Nam’s death. The injuries sustained by Mr. Nam were not self-inflicted,” a criminal complaint obtained by the Des Moines Register says. “Ms. Park stated that the only people present during the duration of the events were her and her husband, Sung Woo Nam.”

Authorities allege Park bound her husband’s hands and feet with zip ties before tying him to a chair in their West Des Moines home on Saturday between 10:30 a.m. and 11 a.m. Park then allegedly stuffed “an item of clothing” into Nam’s mouth to prevent him from yelling in protest before finally using duct tape to place a towel over his head to cover his eyes.

Several hours later, at about 5:05 p.m., police say Nam asked to be untied in distress, but his wife refused to free him. Gun finally called West Des Moines police officers at around 6:45 p.m., at which point deputies found Nam unresponsive with ligature marks on the front of his neck and throat. His wife was “performing CPR” on him, authorities said.

“Ms. Park made efforts to hide and conceal the binding items prior to the arrival of emergency personnel,” the criminal complaint said.

Nam was transported to UnityPoint Health-Iowa Methodist Medical Center, where he was pronounced dead.

The next day, Park emailed her students to say she was canceling classes for the following week and postponing their midterm because of a “personnel issue,” according to the Des Moines Register. Park, who was hired at the small liberal-arts college in 2017, was arrested on Wednesday after faculty members saw deputies in her office.

“I witnessed three police officers in the faculty member's office searching through papers and drawers,” Brian Steffen, professor of multimedia communications, told the school’s newspaper, The Simpsonian. “I did see police officers remove a computer from her office. I don’t know whether they took other materials, but I did see them take a computer away.”

A Simpson College spokesperson told The Daily Beast that the school has suspended Park following her arrest and is cooperating with authorities during the ongoing investigation. As of Thursday afternoon, Park’s staff profile page was removed from Simpson College’s website, as was any mention of the assistant economics professor.

“The recent news has left me and other classmates in shock,” Kody Ricken, a sophomore and one of Park’s advisees, told the student newspaper. “We never would have expected her to do anything like this.”

Park received her master’s degree in economics from New York University in 2010 before teaching there as an adjunct professor for five years, a school spokesperson confirmed. She later received her doctoral degree in economics in 2017 from the City University of New York just before joining Simpson College faculty, according to alumni records.

Park is being held on a $5 million bond at Dallas County Jail. It was not immediately known whether she has a lawyer.