In what is believed to be the longest disruption of a college campus since the Virginia Tech shootings, the Delaware County Community College system will remain shut for another day as teams of investigators track the author of a menacing e-mail.

Eight faculty members received the e-mail Thursday that said the writer was "stressed out" and planning to bring guns to the Downingtown and Exton campuses today or tomorrow, said Ralph Burton, police chief in West Whiteland Township, home to the Exton branch.

"We're assuming it was a student," said Burton, "but we can't rule out other possibilities at this point."

More than a dozen investigators - from Burton's department, the FBI, the Chester County Detectives, and the Brandywine Regional Police Department - have been investigating the case.

Agents are tracking the perpetrator's complex e-mail trail through the Internet, and have found the network where the message was sent on Thursday.

The e-mail arrived just 10 days after the shootings at Virginia Tech, where 32 students and faculty were slain by a troubled student, who then killed himself. Unfounded threats and hoaxes at schools and colleges have surged since the Virginia shootings.

Delaware County Community College locations should reopen Wednesday after the expiration of the e-mailed threat, Burton said. DCCC president Jerry Parker would say only that reopening Wednesday was possible. Students should check the campus Web site throughout the day, he said.

"We're making the decision day-by-day," Parker said today. When students do return, there will be a large police presence on each of the five campuses, which are in Delaware and Chester Counties.

Parker said he hoped the school would be able to hold final exams next week, as scheduled, and keep its May 17 commencement date.

"That's our goal," he said.

DCCC enrolled a total of 10,106 students for the spring semester and employs 701 full-time and adjunct faculty members.

Police disclosed new details about the e-mail today, as the campus shutdown attracted national attention.

Those new facts, provided by Burton, include:

The sender set up an account on e-mail provider Hotmail.com just before sending the note, and has not used the account since.

The account's user name contained the last name of a community college student; that student was questioned "at length" Thursday, voluntarily surrendered his home computer, and is not considered a suspect.

The e-mail was sent over the Chester County Library system, but with wireless public Internet access available at the county's 18 libraries, the sender could have used a laptop in any one of the library's parking lots. That makes tracing the message that much more difficult.

Names of the professors who received the e-mail were listed in the order they appear on a college Web page directory, making it likely that the sender took them randomly off that page. "That makes you think he didn't know them personally," Burton said.

Although threats have closed other college campuses across the country sporadically, authorities said the DCCC case appears to be the most extended disruption of a college schedule since the Virginia Tech shootings April 16.

Contact staff writer Jeff Shields at 610-313-8173 or jshields@phillynews.com.

Inquirer staff writer John Shiffman contributed to this article.