Behr was educated at Lawrenceville School and attended Yale University and was admitted to the bar association in 1910.

Behr married Helen Monypeny Newsom on March 1, 1913 at the Church of the Transfiguration in New York City.

After her husband's death, Helen remarried one of his best friends and former tennis partners, Dean Mathey.

[1] Behr was also a well known lawn tennis player, playing on the United States Davis Cup team in 1907.

Behr, with Beals Wright, was also runner up in the men's doubles at the 1907 Wimbledon Championships, losing to Norman Brookes and Tony Wilding in three sets, 4–6, 4–6, 2–6.

[3] Behr continued his tennis career after the sinking of Titanic (see below), and was named to the 1914 U.S. Davis Cup team along with fellow survivor R. Norris Williams.

Sometime after the ship hit the iceberg, Behr met up with Helen, her mother and stepfather, Richard and Sallie Beckwith; and another couple, Edwin and Gertrude Kimball, on the boat deck.