A 28-year-old Rockland woman pleaded guilty Monday in U.S. District Court in Portland to sharing a video of an infant being sexually assaulted.

Bianca Van Valkenburg pleaded guilty to a single count of distribution of child pornography. A more serious charge of sexual exploitation of a minor is expected to be dismissed by the U.S. Attorney’s Office.

She had been indicted in October 2022 and had been scheduled to go on trial Tuesday.

The federal prosecutors filed paperwork with the court that said the investigation began when officers with the sheriff’s office in Hillsborough County, Florida, recovered a cellphone from someone and found a video of an adult sexually assaulting a male infant.

In one of the videos, law enforcement officers were able to hear audio consistent with a location in Rockland, Maine, according to the court papers.

That led law enforcement to conduct a court-approved search of Van Valkenbeburg’s residence in Rockland. During the course of executing the warrant, officers spoke with Van Valkenburg and she admitted that she sent the child pornography to the person in Florida between June and November 2018, according to court documents.

A sentencing date has not been scheduled. A plea agreement submitted to the court states that Van Valkenburg must serve at least eight years in prison to be followed by at least five years of supervised release.

The offense carried a potential sentence of 20 years in prison. The more serious charge being dismissed carried a maximum sentence of 30 years in prison.

She was being held in the custody of the U.S. Marshal’s Service.