"Hard? Hard? You ruined my life!"
Little about Donnie's early years were revealed, other than he had served time for an unspecified assault committed on January 10, 1998. On the same year of his arrest, the BAU had investigated a case in Pittsburgh in which four nurses were killed. At the time, Jason Gideon was the team leader. Their first suspect was Donnie, who was held in jail for two weeks before he was released after his DNA didn't match to that of the killer's. Later, on May 5, Jack Lee Kemper, the actual killer, was arrested while trying to murder a fifth victim, but the accusation still ruined Donnie's life. The media made Donnie a pariah while he was in jail, and not long after he was released, he went to a bar. One man recognized him from the media coverage, apparently thought that he was still the killer, and punched him out of anger, causing him to fall and hit his head hard on the floor. The blow to the head left Donnie suffering from a seizure disorder that required medication to control. He ended up having a nervous breakdown.
Before his arrest, Donnie owned his own construction company, but he spent all of his money paying legal fees for his lawyer after he was arrested, which bankrupted him and caused him to lose his business. In 2012, Donnie's wife Charlotte, who worked as a nurse, left him and took their two daughters, Sophie and Lauren, with her. Since then, he couldn't hold down a job, being fired from twelve jobs in the span of a decade. Five months prior to "Carbon Copy", the divorce that his wife filed for was finalized, and that was about the same time, on September 9, Jack Lee Kemper was executed. When Charlotte became pregnant with another man's child, Donnie snapped and began plotting revenge. This left him vulnerable to the influence of John Curtis, who convinced him to copy the M.O. of killer artist Bryan Hughes, who had been shot and killed by the BAU a few weeks ago.
Soon after killing two victims, Donnie approaches Shannon Lavin, persuades her to sign a petition to get her attention, and then holds her at gunpoint with a pocket pistol, ushering her into her car. Donnie later murders her and leaves her body in a park with a photo of Hotch on it, which was left by Curtis. The BAU, investigating his killings, eventually deduced that Donnie was also copying Kemper, as the victims all worked as nurses, and that they were surrogates for Charlotte. Still thinking that he is the Replicator, they also believe Donnie wants the BAU to pay for ruining his life by making them look as bad as they made him look fifteen years ago. The team eventually deduces that an original suspect of Kemper's killings could be the unsub, and this clue points them to Donnie's direction. The BAU and local police later arrive at Donnie's house, where he shoots at them with a handgun. Donnie then attempts to flee, but is cornered by police and arrested. During the arrest, he spits at Morgan, causing the agent to be rough on him.
In an interrogation room, the BAU attempt to wrangle out of him a confession to the other murders committed by the Replicator. When Blake remarks that it must have been hard for him to have been a murder suspect, he rants on about how their false accusation ruined his life and caused his family to leave him. He then confesses to murdering the nurses, but when the other crimes committed by the Replicator are mentioned, he becomes worried and demands a lawyer. The BAU soon deduce from his behavior that while he was responsible for the deaths of the nurses, he is not the Replicator, but was influenced by the Replicator instead. While the BAU are gone, Donnie calls Curtis; though Curtis's end of the line isn't heard, Donnie is visibly upset. Afterwards, he intentionally overdoses on his medication as means of suicide. Despite the attempt by police to save him, Donnie dies en route to the hospital.
Donnie copied the M.O. of two different serial killers. He first copied Jack Lee Kemper's M.O. of targeting nurses to both serve as a homage to the man who ruined his life and for his victims to serve as surrogates for his ex-wife who took his daughters away from him. After abducting a victim, Donnie would copy Bryan Hughes's M.O.: he would drug them with ketamine in some unspecified way, bore a hole into one of their thighs, and drained their blood from the femoral artery (a large artery located in the thigh with a tube) while the victim was still conscious, and remove their eyelids with a scalpel after the victim died slowly with little pain.
The only differences between the M.O. and that of Bryan's were that the victims were specifically targeted, they weren't drugged with edetic acid (an anti-coagulant), all of the victim's blood was drained into a single bucket instead of glass jars, the victims' bodies weren't left by under-appreciated works of art, the victims' eyelids were removed post-mortem instead of ante-mortem, and their blood wasn't used to make paintings as Bryan did. Judging by his knowledge of Shannon Lavin's personal life and since Sandy Larson was abducted during one of her routines, it can be assumed he also stalked his victims beforehand. During the house shootout, he shot at the BAU and police officers with a large handgun in an escape attempt.
The BAU profiled the Replicator, whom they initially suspected Donnie of being, as a white male in his mid 40s, possibly in his late 50s. He is criminally and forensically sophisticated, so he may be an ex-convict or have law enforcement training. He is also using his victims as a device with which to antagonize the FBI, and the BAU in particular, by copying murder cases that the BAU had closed all over the country. He stalked each member of the team, which means that he is mobile and has the time and means with which to get around, as well as the intelligence to cover his tracks and remain evasive.
For the unsub, it all started fifteen years ago with the case of Jack Lee Kemper, who killed four nurses and tried to kill another before being arrested and executed. Because the three exsanguination victims were also nurses, this case holds some kind of meaning to him. He could be a member of Kemper's family, friends, or associates, who may be trying to avenge his death or might be convinced that he was wrongfully accused. He could also be a friend or relative of the victims, who may blame the BAU for not being able to solve the case fast enough. This unsub is intelligent and highly organized, but he is also focused on revenge, which makes him very dangerous.
- January 10, 1998: An unspecified charge of assault
- Donnie bears some close similarities to Dylan Kohler. Both were organized serial killers who worked menial occupations at the time of their killings, copied the M.O.s of executed serial killers with several notable differences, and operated under an extremely short time-period that made their killings resemble those of spree killers.
- Scott Grimes, the actor who portrays Donnie, had previously portrayed serial killer Alex Tilden in the Showtime drama series Dexter.
- According to his file from the Department of Corrections, Donnie's Social Security number is 984-00-1028.