A few years ago, a fast-growing startup, adding staff at a breakneck pace, hired a facilities manager as a contractor without asking too many questions.
That startup was Yammer, now part of Microsoft. And that contractor - Marcus Tillman - is now behind bars, facing the 40-year sentence he dodged in Georgia years ago.
Federal investigators, acting on a tip from authorities in Georgia, went to Yammer's office in San Francisco last week seeking information about Tillman, known to his colleagues as "Stephen Warner."
"They were more than cooperative once we told them what was going on," Deputy Joe Palmer told ReadWrite.
Within days, and with help from the information Yammer provided, Palmer and his colleagues arrested Tillman at the Cup-A-Joe Coffee House in San Francisco Thursday night. Tillman was taken into custody, awaiting extradition to Georgia.
“We are as shocked and saddened as anyone to learn of these developments," a Microsoft spokesperson told us. "While we do not want to comment on a criminal matter, we can confirm that at no point was Tillman a Yammer or Microsoft employee. Tillman was a contractor assigned to facilities-related work. We cooperated with authorities in his capture and are relieved that he has been brought to justice.”
"America's Most Wanted"
In February 2009, facing trial on two charges of child molestation, Tillman cut off his ankle monitor and fled. He was convicted in absentia and sentenced. Later that year, he used a bank account opened in Atlanta to purchase a ticket at a California bus depot, drawing attention from authorities in that state. But after that, the trail appeared to have gone cold.
Tillman made several appearances on "America's Most Wanted." But until last week, he lived relatively openly in San Francisco, albeit under his assumed name. Early employees remember him working at Yammer as long ago as 2010 or 2011. His duties included stocking the refrigerator, cleaning common areas, and fixing broken equipment.
He was a constant presence at Yammer's office - including occasions when parents brought their children to work.
Surrounded by some of the industry's brightest software engineers, Tillman appears to have excelled instead at the dark arts of social engineering, or manipulating people to his own ends.
It's not clear how Yammer hired or paid Tillman. Our sources disagree on whether he worked through an agency or as an independent contractor: It appears that his status varied over the years, and that Tillman may have used these changes in payment arrangements to deflect suspicions.
Surrounded by some of the industry's brightest software engineers, Tillman appears to have excelled instead at the dark arts of social engineering.
After Microsoft bought Yammer, a maker of tools for collaboration and information sharing with businesses, for $1.2 billion in the summer of 2012, Tillman's employment arrangements became a subject of talk at the Yammer office. Microsoft does not work with independent contractors; instead, it employs them through agencies.
At the time, Yammer employees recalled discussing a widely held belief in the office that their facilities manager did not have a Social Security number. One explanation that circulated around the office: Warner's religious beliefs forbade him from getting a government-issued identification number.
But any suspicions came up at a time when Yammer was preparing hundreds of employees for a new parent company and a simultaneous move into a new office in San Francisco's Mid-Market district. Contractor or not, Tillman had worked as "Warner" for years at that point.
One thing is clear: Had Yammer hired him as a regular employee, its practice of conducting criminal background checks - an unusual scruple for a startup of its size - would almost certainly have caught Tillman's subterfuge.
Instead, he was able to pull an elaborate deception on the place where he worked for years, exploiting loopholes and perhaps the sympathies of the people whose desks he repaired and whose cafeteria he cleaned.
We asked Microsoft for the name of the agency or agencies through which it and Yammer had contracted with Warner over the years. The company declined to name them.
The software giant has slowly been integrating Yammer's operations. The companies will combine their sales teams in July. In October, human resources and finance operations will shift over to Microsoft's central groups.
Mugshot courtesy US Marshals; photo of Yammer office by Robert Scoble