From her days as a local politician to her role as the US Senate's chief intelligence overseer, Dianne Feinstein has been forced to confront human wickedness on levels personal and political.
As a San Francisco official she held a slain colleague in her arms moments after a gunman's bullets cut him down.
As chair of the Senate Intelligence Committee since 2009, she has been privy to details of the war on terror and extremists who have killed Americans.
Feinstein pushed back against the savagery this week, in a way that could define her career.
She released a 500-page report summary detailing ghastly interrogation practices by the CIA which she and others say amount to torture of detainees.
It capped a years-long effort to investigate and expose the enhanced interrogation techniques of the Central Intelligence Agency, whose leaders she infuriated last March when she dropped a bombshell by publicly accusing its agents of spying on Senate computers.
"I have grave concerns that the CIA's search may well have violated the separation of powers principles embodied in the United States Constitution," Feinstein declared in a dramatic floor speech.
The case recalled the dark years of the agency, and Feinstein said it pained her to expose it to the public.
It triggered one of the worst rows between Congress and the intelligence community, but the matter was too grave to ignore.
As investigators put finishing touches on their massive probe, she said, the CIA breached Senate computers in a bid to delete files confirming the committee's suspicions.
It was amid such frayed ties that Feinstein, following an intense tug-of-war with the CIA and White House, released a declassified version of the report Tuesday, offering 20 damning conclusions about the ineffectiveness and brutality of many post-9/11 interrogations.
"Excellent," is how Senator John Rockefeller described Feinstein's performance this week.
"I've worked really closely with her," Rockefeller told AFP on Friday.
"We've dealt with the same issues. I sit right beside her, and I think she's done a wonderful job."
Feinstein, 81, has lost none of her fighting spirit, but the intensity of negotiations over the report appears to have left a mark.
Approached by reporters as she headed to yet another classified briefing ahead of the report's publication, she said "I don't even know what day it is."
Since entering the Senate in 1993, Feinstein has become one of the US elected officials most knowledgeable about her portfolio.
Twice a week, the committee meets behind closed doors to receive briefings by top intelligence officials.
In 2011 the CIA called her the day before special forces conducted their raid against Osama bin Laden.
Feinstein grew up in the liberal stronghold of San Francisco. It was a political baptism by fire.
She became mayor in 1978 under tragic circumstances, after she discovered the bodies of mayor George Moscone and supervisor Harvey Milk seconds after they were shot.
"I found Harvey on his stomach. I tried to get a pulse and put my finger through a bullet hole. He was clearly dead," she recounted to the San Francisco Chronicle in 2008.
Feinstein has campaigned relentlessly for stronger US gun laws. After a school massacre in Newtown, Connecticut in 2012, she introduced an automatic weapons ban in the Senate. It failed.
She joins Senate Republican John McCain in calling for closure of the US military prison at Guantanamo Bay, Cuba, where more than 100 remain detained.
While she votes liberal on many social and economic issues, Feinstein has faced criticism from civil liberties groups for staunchly supporting the National Security Agency.
Following Edward Snowden's explosive revelations in June 2013, she defended NSA surveillance methods.
"If you sit, I think, in our shoes, you want to protect America," she said.
The "Prism" program that intercepted electronic communications on Facebook and other websites abroad was vital, she insisted.
And Snowden? Feinstein slammed his revelations as "an act of treason."
When ambitious reforms were introduced that would rein in the NSA and unambiguously end its systematic collection of telephone "metadata" from millions of Americans, she sought to water them down.
"On human rights protections she can be very, very, very strong," American Civil Liberties Union senior legislative counsel Chris Anders told AFP, adding that Feinstein's torture report will have an impact for the next 50-100 years.
"But yes, on surveillance issues it's been a difficult relationship." afp, photo by Robyn Beck