Columbia University was accused of antisemitism four years ago by an undergraduate who complained of a “severely pervasive and hostile environment” on campus, but the US Department of Education didn’t open an investigation into his claims until this month.

Jonathan Karten first urged the Education Department in 2019 to investigate whether the school’s actions violated Title VI of the 1964 Civil Rights Act, which bars discrimination based on race, color or national origin. Investigators interviewed Karten in 2020 but took no formal action, according to his lawyer.