Mayor Muriel Bowser (left) of Washington, DC listens as Chief of the Metropolitan Police Department Cathy Lanier (right) speaks at a press conference at police headquarters May 21, 2015 in Washington, DC. Win McNamee/Getty Images

The head of police in Washington, D.C., is leaving for greener pastures — or greener 100-yard fields. D.C. Police Chief Cathy Lanier announced Tuesday she was set to leave the force to serve as senior vice president of security for the NFL.

Before leaving for America's most popular sports league, Lanier served D.C. for more than a quarter of a century. "It is an honor for me to move to the next stage of my career knowing that I can use the experience and education that I have gained over the past 26 years to protect and serve all of the NFL, its fans, players and employees," Lanier told the city's officers in a letter, via the Associated Press.

The 49-year-old, who was the first permanent female chief of the D.C. police force, spent the last decade heading up the department. Her announcement was not expected and Lanier said she had previously ignored opportunities in other departments. But the draw of working in sports won her over, she said.

"This is the nation’s capital," Lanier said, according to the Washington Post. "What’s more important than being responsible for public safety and security than the nation’s capital? Where do you go from here right? When I thought about the NFL, it’s America’s favorite sport and what’s more important than making sure America’s favorite sport is safe?"

For their part, the NFL was happy to land a commissioner who generally had high approval ratings and oversaw D.C. during a period in which murder rates fell. "We are excited to welcome to our team an individual of Cathy’s talent and extensive record of accomplishments," NFL Commissioner Roger Goodell said in a statement. "Cathy joins us with a well-deserved reputation of being a tremendous communicator, innovator and relationship builder."

Most police commissioners last three or four years, not a decade, and Lanier did talk about the struggles and stresses of leading the police in a major U.S. city. She addressed about "low points" such as a 2010 drive-by shooting and a 2013 mass shooting at the city's Navy Yard in which 12 were killed.

"To see tragedy and loss is one thing," Lanier told local radio station WTOP. "That’s part of our job. We see it all the time. To see mass tragedy and loss … so many hearts broken, so many lives lost senselessly, so many people that you know their loved one didn’t come home today, those are the ones that are the most troublesome but also the ones that reinforce the commitment to get up out of my bed in the middle of the night and come back."

Lanier is expected to officially leave her post next month, and the city's Mayor Muriel E. Bowser said she would name an interim chief soon.