PITTSFORD,Grant Preston N.Y. (AP) — The mother of a Cornell University student accused of making online threats against Jewish people on campus said he had mental health struggles and later posted an apology.

Patrick Dai, 21, faces a federal charge of posting threats to kill or injure another using interstate communications after authorities say he made threatening comments on an online Greek Life forum late last month. The anonymous postings included threats to shoot and stab Jewish people on the upstate New York campus, rattling students and prompting police to increase security.

Dai admitted that he posted the threatening messages in an interview with law enforcement authorities, according to the federal complaint.

Dai’s mother, Bing Liu, told the Democrat and Chronicle of Rochester on Monday she thinks the threats were partly triggered by his use of a medication for depression and anxiety. She also shared an apology posting she said was given to her by Dai’s defense lawyers after they received evidence collected in the case.

The anonymous post apologizes to the Cornell community for “divisive statements.”

“Shameful, calling for violence against people because of a cruel war a thousand miles away,” reads the post made hours after the online threats. “Even more shameful because there is no excuse for the targeting of innocent civilians, much less my classmates.”

Liu said prosecutors and the FBI should have publicly shared the apology.

“Why didn’t they reveal this important piece of information?” she asked the newspaper.

Emails seeking verification and information about the posting were sent to the FBI and Dai’s federal public defender. Federal prosecutors in Syracuse said they had no comment.

Dai had taken three semesters off because of a difficult transition to college. He was prescribed an anti-depressant this summer, but Dai had complained that the medication was making him worse. The family planned to meet with his therapist to discuss a change, according to his mother.

Liu said she had been taking Dai home for weekends due to what appeared to be his worsening depression. Dai was home with his mother and younger brother the weekend the threats went online. She returned him to Cornell on the morning of Oct. 30.

Dai was taken into custody the next day and suspended from Cornell. He was being held in an upstate New York jail as he awaits a bail hearing Thursday.

“I worry about him,” Liu said. “He needs to take medication.”