As the man accused of killing Annie Le GRD ’13 advances through the justice system, Yale has updated its policy and procedures for preventing workplace violence.

In an e-mail to all faculty and staff Monday, Vice President for Human Resources and Administration Michael Peel announced several changes to the University’s workplace violence policy in response to Le’s murder and the arrest of former employee John Petrini for bringing a gun to a Yale building last month. The changes were designed to bolster security, specifying behaviors that will not be tolerated and procedures for reporting them.

The updates follow a Sept. 30 message in which University President Richard Levin announced administrators were reviewing security policies.

“We felt it was important to re-publicize the policy in the current environment,” Levin said by phone Tuesday night.

The revised policy now requires all University employees to report threatening, intimidating or violent behavior on campus to authorities. Immediate threats of violence should be reported directly to Yale police, while other prohibited behavior must be brought to the attention of supervisors, deans, the human resources department or other officials, the policy says.

While the University has asked workers to notify superiors of such incidents since before the policy was updated this week, Peel said, the procedures for doing so are now more explicit. The policy now also provides specific examples of “prohibited behavior,” including threats, physical intimidation, stalking, sexual harassment or assault, vandalism, arson “or any other dangerous behavior” in addition to physical violence. The FBI and the Occupational Safety and Health Administration recommend that employers spell out specific prohibited behaviors and require employees to report incidents of those behaviors.

Yale’s policy also bans carrying or keeping a weapon on campus. Violators of the ban may be fired, expelled or charged with a crime. Peel said the weapons prohibition has always been part of the University’s stated policies, but that administrators decided to integrate the ban into the revised document to combine all regulations about preventing workplace violence.

Most of the revisions apply immediately, though a new procedure for conducting background checks on employees will take effect on Jan. 1, 2010. The University already requires all full-time staff and faculty to undergo background checks. But as of next year, other kinds of workers ­— including postdoctoral associates and fellows, employees who come to Yale through outside vendors and contractors, consultants and casual employees who work 30 days or more — will also be subject to background screenings.

Administrators also recently created a new e-mail address, security.suggestions@yale.edu, for members of the community to contact with ways of improving security. The account has already received “many” ideas, Peel said in his message.

Peel said the University had been planning to update the violence prevention policy following a routine review this summer, when a group of administrators and officials, including Yale Police Department Chief James Perrotti, members of the department of security and Deputy Secretary Martha Highsmith, gathered to examine the existing policy, using other universities’ policies as a starting point. But the security breaches this September — Le’s murder and the Petrini incident — spurred the changes, he said.

“Our experiences this fall certainly made it more urgent,” he said in a phone interview.

Before this week, the University last revised the document in 2000 or 2001, he added.