Emporia State University says an investigation has found no evidence to support hate crime or discrimination allegations made by a black couple while they were working for the eastern Kansas school.

In a letter released Wednesday, interim President Jackie Vietti says the investigation into allegations made by assistant professor Melvin Hale and his wife, Angelica, did find areas for improvement within the School of Library and Management, including a need for a "more open environment" that values different opinions.

The Hales say they've endured a hostile work environment since reporting in April that someone wrote a racial slur in Angelica Hale's graduate assistant's office. She later resigned because of what the couple called the department dean's refusal to investigate the complaint.

Melvin Hale on Wednesday called the investigation "a sham." The couple are planning a protest march next Tuesday.