Robert B. McKeon, the founder and chairman of Veritas Capital, the private equity firm that invested in defense contractors, died Monday in an apparent suicide, The Observer has learned.

The state medical examiner’s office in Connecticut, where Mr. McKeon owned a home, said that a man of the same name and age died of “asphyxia due to neck compression,” and that the death was ruled a suicide. The examiner’s office wouldn’t give a time or place of death. The Darien, Conn., police department said in a written statement that a man named Robert McKeon was found dead in his Darien home on Monday, and that “the death is not considered suspicious, but the incident is under investigation pending the results of the scheduled autopsy.”

Veritas’s Mr. McKeon was the Bronx-born son of a deliveryman for Drake’s cakes and a graduate of Fordham University and Harvard Business School. After rising to director at First Boston, he helped found Wasserstein Perella & Co. in 1988, serving as head of private equity and later chairman of the boutique investment bank.

In 1992, on the heels of the successful turnaround of the cosmetics company Maybelline, Mr. McKeon decamped to start Veritas Capital with a fellow former Wasserstein Perella banker named Thomas Campbell.

That same year, Crain’s New York Business found it unlikely that the “boyish-looking” Mr. McKeon “will ever be one of those archetypal, ruthless corporate raiders everybody loves to hate.”

Nonetheless, Mr McKeon’s career was not free from scandal. In 1999, a consultant to Veritas confessed to paying kickbacks to the Connecticut official who approved the state’s $125 million investment in a Veritas fund, and Mr. McKeon refused the state’s requests to refund its investment on the grounds that Veritas had no knowledge of the scheme.

Later, Mr. McKeon would sometimes garner negative attention for his investments in scandal-ridden defense contractors, such as DynCorp, which was embroiled in a sex-trafficking scheme in Bosnia in the 1990s, and MZM Inc., a military contractor that was being investigated by the federal government over suspicions that its owner bribed a California congressman to deliver hundreds of millions of dollars in government contracts. In each case, Veritas acquired the companies after their troubles.

Most recently, Veritas acquired Thomson Reuters’s health care business for $1.25 billion cash earlier this year.

Mr. McKeon was an art collector and a supporter of charities including the Nature Conservancy of East Hampton and the New York Police & Fire Widows & Children’s Benefit Fund, according to an emailed statement from Veritas. He was a trustee at Fordham University, his alma mater, and endowed a fellowship for military personnel at Harvard. He was a member of the Council on Foreign Relations, where he endowed a series of lectures on military strategy and leadership.

“Bob was an extraordinary person, a consummate professional, and a cherished friend and colleague,” Veritas said in the statement. “We are all deeply saddened by this tragic loss and have his family in our thoughts. We are continuing to oversee operations at Veritas and at our portfolio companies, consistent with our regular practice and as Bob would have wanted.”

Veritas said that Ramzi Musallam—who has worked at the firm since its founding—and fellow senior partners Hugh Evans and Benjamin Polk are running the firm.

A phone call to a number believed to be the McKeons’ Darien home was not answered.

This story has been updated to include information on the Veritas senior partners now running the firm.