Female referees in the NBA

Lauren Holtkamp talks with fellow referees Eric Dalen and Scott Foster at a Pistons-Bobcats preseason game in 2012.

Dee Kantner, who along with Violet Palmer became the first female NBA referees in 1997, makes a call against the Wizards on Dec. 4, 1997.

Violet Palmer reasons with Blazers coach Terry Stotts on April 11, 2014.

Brenda Pantoja runs the court during a preseason game in 2013.

Violet Palmer speaks with then-Pistons point guard Jose Calderon on Feb. 8, 2013.

Brenda Pantoja speaks with then-Magic point guard Jameer Nelson at a Dec. 3, 2012, game.

Violet Palmer speaks with Clippers forward Blake Griffin at a Nov. 28, 2012, game.

Violet Palmer confers with fellow referee Courtney Kirkland at a Jazz-Spurs game Dec. 14, 2013.

Lauren Holtkamp huddles with referees David Jones, left, and Tony Brown during a Celtics-Heat game Jan. 21, 2014.

Lauren Holtkamp stretches before a Heat-Celtics game Jan. 21, 2014.

Brenda Pantoja makes a call in a Hawks-Nuggets game on Nov. 7, 2013.