PORTLAND, Maine — Nancy Torresen didn’t become the first female U.S. District judge in Maine on her own.

“I didn’t get here by myself,” she said at her formal investiture ceremony Thursday afternoon at the Edward T. Gignoux U.S. Courthouse. “All the women in this room owe a debt to the women, the suffragists, who fought for the right to vote.”

Torresen, 52, of Bangor also spoke of the women who fought for equal rights for women in the 1960s and made it possible for women like herself to attend law school without having to be the first female on campus.

“I salute the women who came before me,” Torresen told the packed courtroom. “I stand on their shoulders. I hope my shoulders will support the wave that comes in my footsteps.”

Torresen has been on the job since Oct. 11, a week after she was confirmed by the U.S. Senate. The former federal prosecutor replaced U.S. District Judge D. Brock Hornby, who transitioned to senior status last year.

In her seven months on the bench, Torresen has taken on several high-profile cases, including Occupy Augusta’s challenge to a state law that forbids overnight camping in Capitol Park.

In December, Torresen upheld Occupy Augusta’s right to protest in the park across from the State House but found that the no-camping rule and the requirement that demonstrators apply for a permit were reasonable restrictions on their constitutional rights. The judge on Wednesday approved a settlement in a class action lawsuit that would allow young adults with disabilities to have more choice in where they live.

Thursday’s ceremony was a who’s who of the state’s judiciary and political elite. Many of Torresen’s former colleagues from the U.S. Attorney’s Office and defense attorneys with whom she sparred in court also attended the nearly 90-minute ceremony.

Chief 1st Circuit Judge Sandra Lynch, 1st Circuit Judge Kermit Lipez, Chief U.S. District Judge John Woodcock, and Hornby were on the bench to oversee her official swearing-in.

Former U.S. Sen. George J. Mitchell spoke at the event, as did U.S. Sens. Olympia Snowe and Susan Collins, who supported Torresen during the nomination process. U.S. Reps. Mike Michaud and Chellie Pingree, who sent Torresen’s name to the White House in late 2010, also attended and offered their congratulations.

In March, President Barack Obama announced her nomination, and in May the Senate Judiciary Committee recommended that Torresen be confirmed.

“She was unanimously confirmed by the Senate,” Snowe said. “Now for the U.S. Senate to agree to anything, let alone unanimously, is a miracle.

“I believe Nancy’s combination of strong academic credentials and robust professional and real world experience will continue to bestow tremendous credibility upon the position of U.S. District judge for Maine, as her predecessor Judge Hornby did,” Snowe continued in a more serious tone.

Collins teased Torresen about not being born in Maine, but praised her work on one of the last cases she handled as a federal prosecutor.

“In 1990, she demonstrated the great wisdom that we look for in judges by moving to the great state of Maine,” Collins said. “Her service at the U.S. Attorney’s Office and the Office of the Maine Attorney General was exemplary. Her diligence and determination to serve the people were fully demonstrated by her expert work in bringing to justice the so-called ‘Burly Bandit’ in 2010 by coordinating the prosecution of crimes committed across six states.”

Pingree and Michaud said Torresen’s background made her highly qualified for the job.

Mitchell advised Torresen to take a fair and reasoned approach to the rule of law.

“Our economic and military power are recognized [by other nations] and impressive, but it is our ideals that have been and remain our primary influence in the world,” he said. “One of those ideals is our independent judiciary and the rule of law as it is applied to every individual and to government.”

Mitchell was a U.S. District judge in Bangor from November 1979 to May 1980, when Gov. Joseph Brennan appointed him to fill the unexpired term of U.S. Sen. Edmund S. Muskie, who joined Jimmy Carter’s administration as secretary of state.

Appointments to the federal bench are for life. The salary of a U.S. District judge in 2011 was $174,000 per year, according to information on the website for the federal court system.

Torresen first joined the U.S. Attorney’s Office in 1990 and initially handled civil matters involving federal agencies. In 1994, she was assigned to the Appellate Section of the Criminal Division of the Maine Attorney General’s Office, where she primarily was responsible for representing the state in appeals of serious violent crime convictions.

In 2001, she returned to the U.S. Attorney’s Office and was responsible for investigating and prosecuting federal crimes.

From 1988 to 1990, Torresen worked at the law firm of Williams & Connolly in Washington, D.C. She served as a law clerk to former U.S. District Judge Conrad K. Cyr from 1987 to 1988.

Torresen received her law degree in 1987 from the University of Michigan Law School and her undergraduate degree in 1981 from Hope College in Holland, Mich.

She is married to lawyer Jay McCloskey, who served as U.S. attorney for Maine under President Bill Clinton. The couple live in Bangor and have three children.