Originally appearing while the city was facing the first attack by Judge Death of the Dark Judges (a group of undead Judges from another dimension who seek to destroy all life on the basis that only the living commit crime) she was instrumental in stopping the attack. She has since been involved in tackling many other attacks by the Dark Judges, who even managed to use her as an instrument of their plans for in one such attack, tricking her into opening the gateway to their own dark dimension.
Over time, Anderson has become a prominent member of Psi Division, and although she has become critical of the weaknesses evident in the Judicial system of Mega-City One, she is deemed too valuable to lose. In contrast to Dredd, she has a sense of humor and she is able to form personal friendships with fellow Judges, but her resourcefulness and tenacity mirrors Dredd's own and the two have been able to co-operate effectively during a number of important missions.
Anderson has had a crisis of conscience following the resurfacing of childhood memories of an abusive father (as told in the story Engram). She was shocked to find that her Division had set mental blocks in her mind to make her forget this abuse when they inducted her into The Academy Of Law to train as a judge. Though she understood the Division's belief that she was more effective without those scars threatening her mental health, she still felt embittered towards what she saw as another example of the way the Department attempts to control and pervert the truth for its own purposes. Anderson quit Justice Department after an experience on Mars where an encounter with her old nemesis Orlok and an alien race who claim responsibility for sowing the seeds of life on Earth convinced her of the futility of using violence and control to achieve temporal goals. She and Orlok both abandoned their respective roles, and embarked separately upon itinerant soul-searching across the various parts of the galaxy colonised by humanity. In the Dredd stories Tale Of The Dead Man/Necropolis, the character quit the force following similar concerns, bu characters have reconciled their doubts concerning the role of Justice Department to return to serve the city. They are both now considered veterans and regarded with awe by younger and less experienced Judges.
After a deadly run in with Judge Death, Anderson was placed in a coma and infected with the psychic Half Life virus that would be released if she ever awoke. She was able to contain the virus within a web of psychic constructions and illusions, but she was slowly dying. A team of Psi-Judges was sent in to rescue her and destroy the virus; they succeeded in rescuing Anderson, at the cost of nearly the whole team, but Half Life passed on to Judge Gistane, who was then experimented on by the mad Judge Fauster so he could use the virus to achieve immortality. When Half Life was unleashed on the city causing a wave of mass murder, Anderson was the one who stopped it.
Since exiting her coma, Anderson is still dealing with her increasing age; she is now pushing fifty and since being a Psi stops her from using the drugs & treatments that keep aging Street Judges active, she knows she will eventually be unable to do her job anymore. She will eventually meet a tragic yet inevitable end.
In February 2014's Judge Dredd Megazine #345, the Anderson/Psi-Division story ends with Anderson apparently committing suicide via hanging, echoing the death of her friend, Judge Corey. Alan Grant had been talking about such a storyline for some time, implying at LSCC last year that he saw it as the only logical conclusion for the character, and it seemed like a typically emphatic response from the character to the events of the Dredd epic storyline, the Day of Chaos, with Anderson despairing in the face of almost a billion deaths. It later transpired that Anderson's suicide attempt was in fact the result of psychic manipulation by Algol Rey, a former psi-cadet who had been murdering a series of psi-judges in twisted revenge for his own treatment at the hands of the Department.