[7] His father, William Krasner, was the son of Russian Jewish immigrants, an author of crime fiction, and his mother, Juanita Frazier, was an evangelical Christian minister.

[9] He opened his own law firm in 1993[2] and worked as a criminal defense lawyer in Philadelphia for 30 years,[2][11] specializing in civil rights[12] and frequently representing protestors pro bono.

[13] Williams resigned from office and pleaded guilty to federal bribery charges in June 2017; his interim replacement, Kathleen Martin, chose not to run.

[2] Less than three weeks before the primary, a political action committee supporting Krasner's campaign received a $1.45 million contribution from billionaire George Soros.

[15] Krasner's representation of Black Lives Matter and Occupy Philadelphia members led many to call him an "anti-establishment" candidate during the Democratic primary campaign.

[20][21][22] City officials reported voter turnout spiked nearly 50 percent compared to 2009, which was the last contested race for district attorney of Philadelphia.

[18][24][25] As expected, the November general election was not competitive, with Krasner winning almost three times as many votes as his Republican opponent, former assistant district attorney Beth Grossman.

Vega, as a prosecutor, was involved in retrying Anthony Wright on rape and murder charges even after DNA evidence showed another man committed the crime.

[29] During the campaign, Krasner's opponents argued that his criminal justice reform policies had contributed to an increase in violent crime, however some experts say there is no evidence to substantiate this claim.

[36] Krasner also announced that the DA's office had filed a lawsuit against a number of pharmaceutical companies for their role in the city's opioid epidemic.

[38] That same month, Krasner instructed prosecutors to reduce sentence lengths to defendants making pleas, refuse to bring certain low-level charges, and publicly explain their reasoning for pursuing expensive incarcerations to taxpayers footing the bills.

[45] Following the fatal shooting of Philadelphia police officer James O'Connor IV, Krasner faced criticism from William McSwain, a federal prosecutor appointed by Donald Trump.

[46] McSwain, U.S. Attorney for the Eastern District of Pennsylvania, blamed the shooting on a prosecutorial discretion decision by Krasner's office to drop drug charges against suspected killer Hassan Elliott.

Krasner's office dropped drug charges after Elliott failed to appear in court, choosing to approve an arrest warrant for Tyree's murder instead.

Prosecutor spokeswoman Jane Roh responded to criticism by stating that the office believed murder to be a more serious crime than drug possession and charged Elliott accordingly.

[47] On the night of O'Connor's death, Philadelphia police officers formed a human chain at Temple University Hospital entrance to prevent Krasner from entering.

which won a prestigious Peabody Award in June 2022 for "crafting a thrilling series that's both broad and intimate about a man and a movement, capturing what happens when incrementalists meet their match in Big Idea thinkers who want to be doers.

[55] In September, the Pennsylvania House voted to find Krasner in contempt for defying the committee's subpoena for documents related to his prosecutorial policies.