ADT, the nationwide home-security company, says it has purchased Langhorne-based LifeShield from founder Mike Hagan’s Hawk Capital Partners LP for $25 million, two years after Hagan bought the company back from AT&T.

John Owens, who Hagan hired to run LifeShield, the “plug and protect” wireless security system service, will stay in charge, according to ADT based in Boca Raton, Fla.

Founded as InGrid Security in 2004, LifeShield was purchased and renamed by Hagan in 2010, with backing from Michael Bolton’s Novitas Fund, David Berkman’s Associated Group, and other investors. Hagan sold the company at investors’ behest to DirecTV in 2013. Those investors, including Radnor-based NewSpring Capital and Philadelphia-based FirstRound Capital pumped at least $20 milllion into LifeShield in 2009-12 and claimed modestly profitable returns on the DirecTV deal.

LifeShield at first expanded under DirecTV but was repurchased by Hagan after DirecTV became part of AT&T. At the time the company claimed more than 30,000 users, compared to more than one million for a similar service run by Philadelphia-based Comcast.

Hagan previously run the meteoric dot.com company VerticalNet, was an investor in Brian P. Tierney’s investor group that bought the Inquirer and relinquished it in bankruptcy, and had been a CEO of the NutriSystem health food plan, whose board he chaired when it agreed to be purchased by Nashville-based Tivity Health Systems for $1.4 billion in December.

ADT buys smaller "companies that share our passion for security, customer service, and innovation,” said chief executive Jim DeVries in a statement. “Combined with the brand and scale of ADT,” LifeShield should enjoy increased sales, he said.

The Philadelphia-based Morgan Lewis law firm advised LifeShield on the sale, and Raymond James served as financial advisor.