University of Texas at Dallas students said they should have been immediately alerted after a woman's throat was cut on campus last week.
The female student was attacked Friday evening while she was working in the Engineering South building. The victim was able to describe her attacker before she was taken to the hospital, and a campuswide search was conducted.
UTD students said Monday the administration should have immediately warned students.
"As soon as the faculty found out, that's the first thing they should have done," student Jason Lewis said.
Students said they received an e-mail describing the attack more than two hours after the incident, but it should have come sooner.
"This is why things like that happen, things like Virginia Tech happen, is because students aren't notified," student Sylvia Aziz said.
University officials said they were preparing a campuswide warning when the man turned himself in.
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"We began to immediately prepare an emergency campus alert and we were within minutes in sending this when the suspect called and turned himself in," UTD spokeswoman Meredith Dickenson said.
University officials said a man called police about 45 minutes after the attack to say he was the attacker.
John Shaffer, 20, a sophomore computer science major, was arrested by university police at a student-housing complex.
The dean of the engineering school sent an alert to his students and faculty almost immediately after the attack. But students said the entire campus needed to be informed.
"Safety; I mean, I'm a student here, and I have a family to go home to," student Alicia Wilkerson said.
"We'd liked to do it a lot quicker, but the problem is, we had to get a coherent description of the suspect," Dickenson said.
Students said they didn't need a description immediately, just a warning to be on the lookout for a man with a knife.
Shaffer remained at the Collin County Jail on Monday on a charge of aggravated assault with a deadly weapon. Bail was set at $15,000.
Susan Rogers, a UTD spokeswoman, told The Dallas Morning News that she could not elaborate on the attack, what led to it or the victim's current condition, citing student privacy laws.
Shaffer said he did not know the victim, the Dallas Morning News reported Monday on its Web site.