The Washington tech community was stunned to learn last week that entrepreneur and start-up adviser Minh D. Nguyen had been charged with first-degree murder, leaving many to reconcile their image of a helpful and insightful friend with the vacant-eyed mug shot shown in newspapers and on television screens across the country.

That image remains under dispute as questions arise about whether Nguyen inflated his professional background to make his business chops appear more impressive and his track record as an entrepreneur appear more successful.

Among the doubts raised is Nguyen’s chief claim to fame: that he was a co-founder of Silicon Valley software firm Plaxo. Nguyen boasted as much on his LinkedIn profile, and he has used the role as a qualification to advise a plethora of young companies.

At least one of the company’s co-founders, Todd Masonis, is disputing that claim. Masonis said in an interview that Nguyen is a childhood friend of Plaxo co-founder Sean Parker who was given an equity stake in the company without doing any work. Parker is most widely known as the founder of Napster and a former executive at Facebook.

Masonis said he only met Nguyen once in his nine years as a founder and executive at Plaxo — during a brainstorming session before the firm was incorporated. Nguyen may have contributed to the initial idea behind Plaxo, Masonis said, but he never had a title or responsibilities at the company.

Authorities charged Minh D. Nguyen with first-degree murder in connection with a shooting earlier this month. (Loudoun County Sheriff’s Office )

“Literally no one, even the super early people [at the company] had heard of this guy,” Masonis said. “That’s how loose the association is.”

According to the edit history of the Wikipedia page for Plaxo, a user who identified himself as “Nguyen” repeatedly added “Minh Nguyen” to the list of company founders. Each time the name was removed, “Nguyen” would add it again.

Parker, who serves as founder and chairman of San Francisco-based Airtime, did not respond to requests for comment. Requests for comment from Plaxo, which was sold to Comcast Interactive in 2008, were also not returned.

Nguyen, meanwhile, is scheduled for a bond hearing on Jan. 28 and to have an attorney appointed on Feb. 4

Other items on Nguyen’s public résumé were either mistaken or misleading, several sources said.

Nguyen described himself as an adviser to District-based Contactually from November 2011 to present, a title and timeline that one of the company’s founders said is not true.

Chief executive Zvi Band said Nguyen offered informal counsel to executives shortly after the company was formed in late 2011, but that he was never made a formal adviser and their communication ended in early 2012.

“Minh was an informal mentor for a short period of time, and our relationship did not deepen enough to warrant the verification of his claims — nor were we at any point given any reason to be suspicious of his history,” Band said via e-mail.

Nguyen also lists himself as a mentor to young companies at many of the region’s largest incubators, including TandemNSI, AOL Fishbowl Labs and the now-defunct Fort. Organizers or start-ups at each of those entities verified his involvement.

However, Jonathan Aberman at TandemNSI said Nguyen worked as a consultant from April 2014 to November 2014, even though Nguyen listed his dates of involvement as April 2013 to present on LinkedIn. It is unclear when Nguyen’s LinkedIn profile was last updated.

Nguyen also describes himself as a mentor at mHelpDesk, a company in Fairfax that makes software for businesses. Executives there deny Nguyen has any affiliation with the company.

Investigators in the Loudoun County Sheriff’s Office allege Nguyen, 38, shot a man after entering a town home on the 44200 block of Sonora Lane in Ashburn at 9:30 p.m. on Jan. 15. Spokeswoman Liz Mills identified the victim as Corey Mattison, who had married Nguyen’s ex-wife in recent months.

The department has not yet released a motive for the shooting.

Two children were also in the home, but were not harmed. Nguyen’s ex-wife and a third child returned to the home as the shooting occurred, a department spokeswoman told The Washington Post. Neither were harmed.

Officers found Nguyen at the home being pinned down by his own mother, Mills said. He was arrested at the scene and charged with first-degree murder and use of a firearm during the commission of a felony, according to the department.

An early effort to raise money to offset Nguyen’s legal fees was abandoned after the donation page on GoFundMe was taken down for reasons that remain unclear. The page’s organizer and representatives from GoFundMe declined to comment.