Among Solomon's top suggestions for employers is to come up with a comprehensive workplace violence policy. It should be distributed to employees, and given the recent shooting in California, it may be a good idea to redistribute it now with a cover letter explaining it is being distributed in view of recent events and explain how the company has a policy and commitment to maintain a safe environment, Solomon said.

"Every company should have a workplace violence prevention plan," added attorney Michael Crane, senior vice president of Hillard Heintze, a security firm. It should address risk from employees or outsiders, he said.

Actually, employees can play a key role in reducing the risk of workplace violence. Many times there are clues ahead of time that something may take place, according to Solomon. These could include types of behavior, comments made to someone, and other activities that may hint of a potential danger, Solomon says.

"People tend to ignore warning signs," added Thomas Mandler, an attorney at Hinshaw & Culbertson.

Similarly, J. Eric Dietz, director of the Purdue Homeland Security Institute and former executive director of the Indiana Department of Homeland Security, said that people tend to have "an internal voice" which tells them "what is right and what is not" when they see something of concern. He advises people not to put a "positive spin" on their concerns over "odd behavior."

Solomon recommended, too, that employees hear from the company that it cares for their safety, and how they are empowered and expected to report anything that makes them "uncomfortable."

Also, the company should say complaints will be thoroughly investigated, appropriate action will be taken and an employee or employees will not be retaliated against for coming forward, she added.

Training of employees and managers on workplace violence is important and Solomon said more companies are likely considering training after recent incidents. Part of the training could also be used to calm employees who may be afraid that a similar incident could happen at their own workplace, she said.

"Part of the education and training [should be] what are the danger signs of potential violence and how to look for them," Mandler added. Also, having an established policy on how to respond to concerns raised by employees — and making sure it is equally enforced — can help protect a company legally, he added.

Some companies also hold drills with simulations of incidents. But Solomon recognizes there is an expense and time constraint for such exercises.

Some companies also set up hotlines so employees can report concerns. Often, the hotline calls remain anonymous.

One issue at many workplaces is how some employees are reluctant to report concerns they have – ahead of any incident. They may not want to get another employee in trouble or may be concerned if their concerns are wrong. They also do not want to get the employee – who is generating their concerns – angry at them.

But Solomon recommended employees with concerns not wait to say something "if something made you feel uncomfortable … you may have saved lives." Also, one employee's complaint may not be the first one on someone, she added.

Once a complaint is received, a manager needs to take it seriously. Not only is it reported to the appropriate office in a company, the company may sometimes choose to contact law enforcement or a threat assessment specialist – who may be a psychiatrist or psychologist. They can look at the situation to see if a threat is imminent, Solomon said.

"If someone [at the company] tells someone in management or a supervisor [about a concern] the company is put on notice," Crane explained. He said that legally the company has to respond.

While Solomon urges preparation to reduce risk, she confirmed, in reality, "No amount of measures can prevent any incident from occurring. You can never eliminate the risk that one of these incidents might happen."

To reduce the impact of an incident, Jim Hutton, chief security officer at On Call International, recommended that an organization's security department have a close relationship with law enforcement.

He further recommended that first responders — including police and other law enforcement, firefighters, SWAT teams and EMT/paramedics — have a chance to get familiar with a company's buildings and property. When he was at corporate security posts, (he was chief security officer and director of global security for Procter and Gamble, and chief security officer for The Gillette Co.) Hutton recalled inviting them over after regular workday hours to see the facilities. In that way, they are more effective when and if they need to respond in a critical situation.

Overall, he recommended organizations also set up cross-functional teams, with representatives from such internal departments as legal, medical, human resources and security. That diversity will provide different points of view, he explained. They should think through the layout of a company's campus, ensure training of employees and supervisors, and consider various exposures.

Solomon agreed that a management response team should meet on a regular basis to discuss how the company keeps its employees safe, and discuss various options. The team may want to include an outside consultant when appropriate, she said.

Hutton added it is important to come up with a process and systems to follow in such situations.

"Clearly, the conversation is much more complex now," Hutton said, adding that he suspects "a lot of folks' nerves are on edge right now."

From his perspective, Dietz said the presence of armed security staff "is a very good, positive thing." He noted that the Inland Regional Center, where 14 people were killed and many others injured, is a gun-free zone.

Meanwhile, Hutton advised organizations to "assume no organization would be immune from that type of active shooter."

"These incidents take place all over the place," Crane agreed. "It can happen anywhere."

But Arieh Shalev, a psychiatrist and professor of psychiatry at New York University — who was also the director and founder of the Center for Traumatic Stress Studies at Israel's Hadassah University Hospital — said that recent incidents can lead people to "overestimate the likelihood of another incident." He said the likelihood of something happening is "actually very small" and people need to get back to "reasonable expectations of risk."

"Terror is about psychological attack on our safety," Shalev explained. "Most of us are safe."

If an incident does occur, and someone, tragically, dies, Shalev recommends that company leadership display something he calls "grief leadership." An example is at the New York City Police Department – when an officer is killed, the department's leadership leads officers in grieving. "Make it something shared," Shalev said.

"People don't know what to do with their emotions," he said about the impact from a tragedy. After all, it is a "major loss for everyone."