"The place is a liberal mess, allowing a certain group of crazed lunatics to enter and exit the classroom and spew fake anger and hate," said Trump.
In an interview with NBC's Lester Holt, Garber noted that antisemitism on his campus was a "real problem," but that freezing funding was not the answer.
Signatories of the letter included current and former leaders of synagogues and Jewish organizations across the denominational spectrum.
Presidents of over 100 institutions criticized what is described as "the unprecedented government overreach and political interference now endangering American higher education."
The lawsuit charged that the administration exceeded its statutory and constitutional authority when it engaged in arbitrary and capricious threats of withholding grants.
This comes after the Trump administration announced it would freeze $2.3 billion in funds for the Ivy League university.
The Harvard Square MBTA station was shut down for three hours following the shooting.
The Trump administration "appears to have doubled down on those demands through its deeds in recent days," a Harvard spokesperson said.
Comes as administration freezes $2.2 billion dollars in federal funding and threatens the university’s tax-exempt status.
Trump's administration said it sought Harvard University's records on foreign funding going back a decade and on some foreign ties.