Origin  

Romy Chandler began her law enforcement career as a FBI cadet, but she never saw it through after been warned off by actual agents that the job was more paperwork than anything else. Romy was a black belt martial artist and did not want a career where she would be stuck at a desk most of the time. She then joined the Gotham City Police Department, where she rose to the rank of detective and was handpicked by Commissioner Gordon to join the Major Crimes Unit, where she was partnered with Nate Patton. 

Creation  

Romy Chandler by Ed Brubaker, Greg Rucka and Michael Lark as part of the cast of Gotham Central, a series focusing on the police of Gotham City. 

Major Story Arcs  

In the Line of Duty  

When Mr. Freeze murdered Detective Charlie Fields, the case of kidnapping victim Bonnie Lewis was left in the air. It was the case that Fields and his partner Marcus Driver had been working on when they inadvertently crossed paths with Mr. Freeze. Romy Chandler worked with Driver to solve Fields' final case, which got worse as Bonnie Lewis' body turned up dead. It quickly became clear that the kidnapping and ransom clues were just a diversion for a murder. 
 

Just when it seemed they had burnt up all their leads, Chandler and Driver took a harder look at the married couple Bonnie babysat for. Also, a connection was found between their case and the Firebug case Sarge and Patton were working. They determined that the husband was the new Firebug and killed Bonnie after the girl stumbled upon his Firebug gear while babysitting. The case was closed. but Chandler and Driver were not done with each other. They had grown close in the few days it took to solve the case and soon began a secret relationship, or as secret as a relationship could be when surrounded by detectives. 

Soft Targets  

In the days leading up to Christmas, the Joker went on a killing spree of Gotham City officials, putting a scare into the whole population. He then abducted television reporter Angie Molina and turned himself in to the G.C.P.D., letting them know he left her with a bomb that was counting down at they spoke. As they searched for Molina, it was Chandler who realized the Joker's gag. By turning himself in, he made the people few safe enough to go back outside and resume their Christmas shopping, which meant Molina and the bomb were probably in the back room of a toy store. 
 
Chandler's instinct was right. She and Patton found Molina in the back of a toy store with a bomb counting down from four minutes. It wasn't enough time for the bomb squad arrived. Chandler evacuated the store while Patton worked on freeing Molina from her chains. There was not enough time. Batman swooped in to save Molina as the bomb exploded. Chandler rushed in to the burning ruins to find Patton badly hurt and see Batman taking Molina to safety. 
 
Tragically, Patton's injuries were too severe. He never regained consciousness and after three months was taken off life support. Chandler resented Batman for not saving him. 

Dead Robin  

When the dead body of a boy dressed up like Robin turned up in an alley, the whole Major Crimes Unit was stirred up into a frenzy to find out what was going on. Chandler, still angry at Batman for Patton's death, insisted that he should be the prime suspect. She and her new partner, Takahata, went to the Iceberg Lounge to question the Penguin only to find that Batman had beat them to it. Chandler stormed into the office to find Batman looming over a beaten Penguin. Demanding that he freeze, Chandler shot him when he refused. 
 
Takahata caught up to find her standing in shock and Batman lying on the floor. However, Batman's body armor took the bullet just fine, because he quickly got back up, disarmed Chandler and broke her nose. 
 
Shooting Batman was bad enough, but she had also lost her service weapon. The whole situation spelled doom for her career when Captain Sawyer found out. Fortunately, Stacy was able to get the gun back from Robin, along with the warning from Batman to not shoot him again.