Outsourced and temporary employees have become a major presence in many companies in recent years, and they have their own set of security risks.

“Companies are basically keeping a core staff, and getting rid of the rest of their employees,” said Joseph Musacchio, president and CEO of nextSource Inc., a New York City-based company that provides what it bills as a “one-stop shop” for staffing and related services to companies worldwide, including San Diego. “People want as little in the direct payroll as possible, keeping only what is necessary to run the business.”

All of nextSource’s services are online, including Talent Acquisition Management Solution, or TAMS, and the People Ticker, which calculates market costs for salaried and hourly workers.

When Musacchio started his company 10 years ago, he recalled, “The industry was more decentralized, and managers were hiring temp consultants and clerical work, directly. They had no idea who was in their facility at any given time. After 9/11, everyone wants to know.”

But while most major companies tend to run background checks on in-house staffs, many don’t consider taking the same precautions with their extended work force, said David Nachman, vice president of marketing and business development for Irvine-based HireRight Inc., which offers employment background and drug-screening services around the world, including in San Diego.

“In a tight labor market, a lot of companies start to rely more on an extended work force — temporary labor, or independent contractors and vendors,” he said. “Many companies don’t perform background checks on their extended work force.”

In a recent survey, HireRight found that these workers were 92 percent more likely to have a felony record than a permanent hire, while about 50 percent were more likely to have a misdemeanor record or drug history.

“Over the years, we’ve seen many large employers doing background screening, but, with smaller employers, it is much less common,” said Nachman.

Less desirable employees — those who don’t make it through screenings — are more likely to become independent contractors or work for temp agencies, he said.

“If you hire them and they commit work force violence, and you didn’t get the information that could have been discovered in a routine background check, you could be held liable,” said David Nachman, vice president of marketing and business development for Irvine-based HireRight Inc.

Barry J. Nadell, senior vice president of background screening for InfoLink Screening Services in Chatsworth, said it’s a different world out there.

“It’s not like in the past, when you could call a past employer and get information accurately,” he said. “In today’s world, you are liable if something happens under negligent hiring.”

Nadell, who has served as an expert witness in these types of cases, said the outcomes often hinge on whether or not a business did a background check.