Kruger, 38, a deputy assistant U.S. attorney general, will be the first African American on the court since former Justice Janice Rogers Brown departed in 2005. Like Gov. Brown's two other appointees to the state's highest court, Kruger has a stellar Ivy League resume but no judicial experience.
When Kruger is sworn in next month, the seven-member court will have three justices appointed by a Democrat for the first time since the 1980s.
Kruger told the Commission on Judicial Appointments that she was "deeply honored and humbled" that Brown chose her.
Although she has not practiced law in California, she said she has always considered the state to be her home. She said her government work has exposed her to a wide variety of legal doctrines, from constitutional questions to state and federal criminal matters.
Chief Justice Tani Cantil-Sakauye, who heads the commission, offered Kruger the chance to address criticism by some lawyers that she had not spent enough time in California and lacked judicial experience.
Kruger noted that she grew up in Southern California, has family in the state and was grateful "to have the opportunity to come back home."
Kruger said she realized she was joining a court with justices who have had decades of experience on the bench but promised to bring a useful perspective.
She said her professional experience has taught her the importance of being fair-minded, open and aware of the practical effects of court rulings, and instilled in her "a fidelity to precedent" and respect for the legislative and executive branches of government.
"Every case has to be judged on its own merits and individual facts," she said.
Kruger has argued 12 times before the U.S. Supreme Court on behalf of the federal government. She will be one of the youngest California Supreme Court justices in modern history.
A state bar evaluating committee gave Kruger its highest rating: exceptionally well qualified.
Kruger has "engaged in appellate practice at the highest and most demanding level," advising the president and executive branch agencies on how to resolve disagreements over constitutional and other complex legal matters, the bar reported to the commission.
"She has excelled at all her endeavors and is praised for her intellectual firepower, written and oral advocacy skills, impeccable judgment, her fairness, diplomacy, and her composure under pressure," Jason P. Lee, who chairs the Commission on Judicial Nominees Evaluation, said in a letter to the appointments panel.
Kruger was born in Glendale and attended Polytechnic High School in Pasadena, Harvard College and Yale Law School. Her mother and her late father were pediatricians. She is married and has a 2-year-old daughter.
She told the commission that her mother, who was born in Jamaica and attended Monday's hearing, taught her the value of hard work and the belief that anything was possible.
Kruger's appointment surprised legal analysts. She is not well known in California. Most had expected Brown to nominate a judge to balance out his two prior appointments of law professors.
Though Kruger's nomination triggered some criticism, no one spoke in opposition to her Monday. The hearing lasted less than an hour.
Much of the criticism of Kruger has stemmed from the fact she has lived outside of California most of her adult life.
Former San Francisco Mayor Willie Brown wrote in a San Francisco Chronicle column earlier this month that African American lawyers, law professors and judges had questioned why the governor had not selected a justice from within the state.
"Were there no qualified African Americans in California?" the retired mayor asked.
Gov. Brown will swear in Kruger and Mariano-Florentino Cuéllar, a Stanford University law professor Brown appointed earlier this year, on Jan. 5. Brown's first appointment this term was Justice Goodwin Liu, a former UC Berkeley law professor who has had a moderately liberal record on the court.
The three Democrats are likely to change the tenor of the court. Along with Justice Kathryn Mickle Werdegar, a moderate appointed by former Gov. Pete Wilson, they could form a new majority.
The court has been dominated by Republican appointees for decades. It upholds the vast majority of death sentences and tends to rule for prosecutors instead of defendants. On social issues, such as gay rights, the court has been moderate to liberal.
Kruger will take the seat vacated last April by retired Justice Joyce L. Kennard. Cuellar will assume the seat of Justice Marvin Baxter, who will retire next month.