Kamala Harris was a prosecutor for far longer than she’s been a politician.

Harris’s lengthy career in law started in 1990 when she became a deputy district attorney specialising in prosecuting child sexual assault offenders.

It ran until 2017 when she was overseeing the largest state justice department in the country as attorney general of California.

She says what drove her – and what still drives her – is “a very strong sense of responsibility to protect those who are vulnerable”.

But where did that sense of responsibility come from?

According to her, the catalyst was a devastating situation with her best friend at high school.

Ms Harris, who was raised in Berkeley in California, moved to Montreal in Canada for high school with her mother Shyamala Gopalan and sister Maya after Ms Gopalan, a breast cancer scientist, got a research job there.

It was at West Mount High School where she met fellow student Wanda Kagan, who was also new.

The pair quickly became best friends. But as they grew closer, Ms Harris could sense something was off.

She first spoke about the incident in a video uploaded to her social media in 2020, with permission from Ms Kagan.

“I suspected something, because she would come to school and just be sad,” Ms Harris said in a video.

“And there were times when she just didn’t seem to want to go home.

“And I remember asking her: ‘Is everything ok?’ I just sensed it.”

Her best friend then told her she was being sexually and physically abused by her stepfather.

“And so I said to her as soon as she told me: ‘Well, you have to come stay with us,'” Ms Harris said.

“And a big part of the reason I wanted to be a prosecutor was to protect people like her.”

Ms Gopalan took the teenager in and helped her navigate the system to get the support she needed, Ms Kagan told Sky News in 2020.

Expanding on her experiences last month, Ms Kagan told MSNBC Ms Harris “rescued” her and that she, along with her family, gave her “stability and structured me into believing I could continue my education”.

Ms Kagan, who still lives in Montreal and went on to have a career in healthcare, said it’s been an “emotional ride” to watch Ms Harris go on to “fight for the American people just like she fought for me over 40 years ago”.

“I want them [voters] to see that she’s exactly the kind of person that she’s always been from over 40 years ago in high school when she rescued me and it wasn’t just ‘say something’ – it was ‘do something’.

“She was going to make sure that something was done and to advocate for me even after I went to live with her and her mum and Maya.

“She has those protective instincts. She’s going to do something and fight for the people of America.”

Read more:
Harris criticises Trump for ‘political stunt’ at cemetery
Your ultimate guide to the US election
Former Republican vice-president says he’ll vote for Harris

The childhood friends drifted apart when Ms Harris left Montreal. But years later, when she was a prosecutor, Ms Harris called Ms Kagan and told her the impact of going through those experiences with her had led her to fight for children and women who had been sexually assaulted.

“That was a really special, touching moment when she shared the impact that I had on her life,” Ms Kagan said. “I know she’s always had an impact on my life and where I am today.”

How Harris got here

After finishing high school, she went on to graduate from Howard University and then the University of California Hastings College of Law, which she graduated from in 1989.

The following year she became deputy prosecutor in Alameda County in California, specialising in prosecuting child sexual assault cases, but also working on homicide and robbery cases.

She worked there until 1998 when she was made managing attorney of a criminal unit at the San Francisco District Attorney’s Office before becoming head of the San Francisco City Attorney’s Division on Families and Children.

She became the first female district attorney for San Francisco in 2004. During her first three years in the position, the conviction rate in the city jumped from 52% to 67%.

She served for six years before being elected as attorney general of California in 2010, where she oversaw the largest state justice department in the country.

In 2016, she won the US Senate race in California, beating fellow Democrat Loretta Sanchez who had 20 years’ experience in Congress.

Here, she built a reputation around her work as a prosecutor and gained national attention during her forensic questioning of Trump administration officials including Jeff Sessions, and then Supreme Court nominee Brett Kavanaugh.

She had become a prominent politician by the time she launched a campaign for the Democratic presidential nomination in January 2019, going with the slogan “Kamala Harris for the People”.

Democrats saw her as a promising candidate to overthrow Donald Trump’s presidency in the 2020 election, but Ms Harris ultimately dropped out of the race in December 2019, blaming a lack of finances.

Joe Biden selected her as his running mate in August 2021, describing her as a “fearless fighter for the little guy”.

It made her the first black female running mate for the two major parties, and only the third female running mate for the two major parties in American history.

Fast-forward around three years and President Joe Biden, who was struggling in the aftermath of a disastrous debate against Mr Trump, opted to bow out of the 2024 election and endorse his vice president for his position. She was formally made the Democratic nominee in August.