The co-founder of pre-Facebook social network Plaxo has been charged with murdering his ex-wife's new husband. Minh Nguyen, 38, allegedly shot Corey Mattison two months after he married Denise Nguyen, having broken into the new couple's townhouse in Ashburn, Virginia. Two of Nguyen's three children with Denise were present at the time of the shooting at 9.30pm on Thursday, police said. Shooting: Plaxo co-founder Minh Nguyen (right) allegedly shot dead Corey Mattison, who married his ex-wife Denise in November (new couple pictured together, left). Nguyen has been charged with first-degree murder . Denise walked in with the third child during the attack, according to the Londoun County Sheriff's Office. Nobody else was injured in the attack, the report said, and Nguyen was arrested without incident. He was charged with first-degree murder and is being held without bond. Mattison, who had two elementary-school-aged children of his own, was a project manager at a glass construction company based in Washington, D.C., WPBF reported. His colleagues told the station Mattison spent a lot of time with his children as well as Nguyen's. 'Corey and his wife would go to a baseball game with the kids, and [Nguyen] would blow up,' his colleague Rick Knutson told the station. Attack: Mattison (left) was killed in the shooting at the townhouse he shares with Denise and their children from previous relationships. Denise's three children with Nguyen were present at the shooting, police say . 'Broke in': Nguyen, 38, allegedly broke into the property in Ashburn, Virginia, at 9.30pm on Thursday . 'He would try to prevent them from taking the kids anywhere. The guy seemed to be a little unstable.' Nguyen, a major figure in the US technology business, co-founded Plaxo in 2002 with Sean Parker, Facebook's first president. The site has since been bought by Comcast. The social network described itself as the 'world's leading online address book, storing over 50 million address books with 3.7 billion contacts.' Nguyen, graduated from George Mason University with a degree in Multimedia Design in 1997, is based in Washington, D.C. Tech career: Nguyen co-founded Plaxo in 2002 with Sean Parker (right), who was Facebook's first president . Landmark venture: The pre-Facebook site was billed as an 'online address book' used by 3.7 billion people . Having started out as an interface programmer at AOL, Nguyen's post-Plaxo career saw him take up advising roles at numerous apps and websites. In 2012, he became the founding CEO of App Press, which provided tools for designers to build, manage and deploy apps. He is currently an advisor to for at least three tech firms and the chairman of Syllabuster, a mobile platform for students and teachers.
Minh Nguyen, 38, founded pre-Facebook site with Sean Parker in 2002 .
He 'broke into ex-wife's home and shot dead new husband' on Thursday .
Denise Nguyen married project manager Corey Mattison in November .
Two of Nguyen's children 'were present in Ashburn, VA, home at the time'
Denise 'walked in with their third child during the shooting'
Mr Nguyen arrested at the townhouse, charged with first-degree murder .
The co-founder of pre-Facebook social network Plaxo has been charged with murdering his ex-wife's new husband. Minh Nguyen, 38, allegedly shot Corey Mattison two months after he married Denise Nguyen, having broken into the new couple's townhouse in Ashburn, Virginia. Two of Nguyen's three children with Denise were present at the time of the shooting at 9.30pm on Thursday, police said. Shooting: Plaxo co-founder Minh Nguyen (right) allegedly shot dead Corey Mattison, who married his ex-wife Denise in November (new couple pictured together, left). Nguyen has been charged with first-degree murder . Denise walked in with the third child during the attack, according to the Londoun County Sheriff's Office. Nobody else was injured in the attack, the report said, and Nguyen was arrested without incident. He was charged with first-degree murder and is being held without bond. Mattison, who had two elementary-school-aged children of his own, was a project manager at a glass construction company based in Washington, D.C., WPBF reported. His colleagues told the station Mattison spent a lot of time with his children as well as Nguyen's. 'Corey and his wife would go to a baseball game with the kids, and [Nguyen] would blow up,' his colleague Rick Knutson told the station. Attack: Mattison (left) was killed in the shooting at the townhouse he shares with Denise and their children from previous relationships. Denise's three children with Nguyen were present at the shooting, police say . 'Broke in': Nguyen, 38, allegedly broke into the property in Ashburn, Virginia, at 9.30pm on Thursday . 'He would try to prevent them from taking the kids anywhere. The guy seemed to be a little unstable.' Nguyen, a major figure in the US technology business, co-founded Plaxo in 2002 with Sean Parker, Facebook's first president. The site has since been bought by Comcast. The social network described itself as the 'world's leading online address book, storing over 50 million address books with 3.7 billion contacts.' Nguyen, graduated from George Mason University with a degree in Multimedia Design in 1997, is based in Washington, D.C. Tech career: Nguyen co-founded Plaxo in 2002 with Sean Parker (right), who was Facebook's first president . Landmark venture: The pre-Facebook site was billed as an 'online address book' used by 3.7 billion people . Having started out as an interface programmer at AOL, Nguyen's post-Plaxo career saw him take up advising roles at numerous apps and websites. In 2012, he became the founding CEO of App Press, which provided tools for designers to build, manage and deploy apps. He is currently an advisor to for at least three tech firms and the chairman of Syllabuster, a mobile platform for students and teachers.
ex-wife's new husband. Minh Nguyen, 38, allegedly couple's townhouse in Ashburn, Virginia. Two of Nguyen's three children with Denise were present at the time of the shooting at 9.30pm on Minh Nguyen (right) allegedly shot dead Corey Nguyen has been charged with first-degree murder . Denise walked in with the third child during allegedly broke into the property in Ashburn, Virginia, at 9.30pm on Thursday . 'He would try co-founded Plaxo in 2002 with Sean Parker,