Police Captain Jean DeWolff first became involved with Spider-Man when he fought against a criminal impostor who framed the web-slinger while committing a series of robberies. The impostor was defeated and left for DeWolff to arrest.
DeWolff later personally met Spider-Man after he defeated Gladiator who was holding a group of hostages in a museum. She was the first police officer who did not try to shoot Spider-Man on sight, and ordered her police squad not to arrest him. Spider-Man was pleased to have an ally in official law enforcement, and DeWolff continued to help him whenever he needed help. However, during the gang war against Hammerhead DeWolff had been secretly working with the Kingpin for some length of time and had been manipulating Spider-Man to do New York City's mastermind's own doings.
When hitman Frank Oliver (the Kangaroo) posed a threat to the Kingpin, DeWolff manipulated Spider-Man and New York City's other vigilantes to eliminate him. DeWolff arrived on the scene of Kangaroo's arrest and was shot by the Punisher, killing her. Spider-Man was informed by the Punisher and Daredevil of DeWolff's associations with the Kingpin and her manipulations.
After Jean DeWolff's death, she was succeeded by Frank Quaid. Quaid, unlike the corrupt DeWolff's, honestly helped and supported Spider-Man.
Jean DeWolff's last name was previously changed to "De Wolff" by Brian Michael Bendis, until being reverted in later appearances. It is unknown for the name change, but given that early on Bendis was not consistent on Kenny McFarlane's name, it's possible that the name was a continuity error.