"Maybe you gotta sit with the past before you can walk away from it."
Sheriff Merrill Dobson is an incidental character who appeared in The Angel Maker.
Background
Dobson was Sheriff at the time Cortland Bryce Ryan killed six women in New Canaan, Ohio. Before the murders, a homicide was never seen locally in over three decades, thus the town was left terrorized. During the investigation, he befriended Sela Dobson, whose only daughter was one of Ryan's victims. In 1998 or 1999, Ryan was eventually captured during an attempted break-in, tried, found guilty of the murders, and sentenced to death. He was executed by lethal injection on September 16, 2007, after several complications. On the one-year anniversary of the execution, another woman was killed with Ryan's M.O., with Ryan's semen being found in her body. This stoked a resurgence of terror in the community, leading to Dobson calling in the BAU.
The Angel Maker
Dobson shows Hotch and Reid the crime scene, all the while saying how the latest murder has gotten people to think that Ryan may have returned from the grave. When Reid realizes that all of the windows in the house were opened up, one of Ryan's signatures, Dobson tells them that this detail was never released to the public, not even during the trial. Hotch and Reid then give a preliminary profile on how the unsub knows intimate details of the investigation. When Dobson asks about the semen found in the victim's body, Hotch tells him that it may have been smuggled out of the prison, kept on ice, and brought out on the anniversary of the execution. Reid then informs Dobson about an actual industry specializing in serial killer effects and memorabilia.
Later, someone sends the local newspaper a letter in which he claimed to be Ryan. This leaves Dobson in distress, which is magnified when Reid realizes the letter could be authentic. Soon afterward, Sela arrives and asks about the letter, saying that he could not expect to cover up something like that. Dobson denies that the letter was actually sent by Ryan, but Sela tells him about rumors spreading around town, that there were problems during the execution. She then suggests that Ryan might still be alive and shows him a street view of the panicking townspeople as proof that others believe it as well. To assure the citizens that Ryan is truly dead and buried, Dobson has Ryan's body exhumed, despite the BAU's protests that this is only indulging the unsub by perpetuating his ruse, and that it may lead to more murders. Once the coffin is unsealed, everyone is shocked to find that it is empty.
Eventually, the BAU release a profile that Dobson and his Deputies listen to; it identifies the unsub as a woman who is a groupie copying Ryan's M.O. Later, another woman is murdered, and Dobson leads Hotch and Morgan to the crime scene. He then tells the BAU about an attack on a woman committed by another woman, though the attack was disorganized and did not match Ryan's M.O. The assailant was later identified by Prentiss as Shara Carlino, another "fan" of Ryan's. Eventually, a large amount of digging through Ryan's correspondence with his "fans" leads to the BAU realizing that the unsub impregnated herself with Ryan's child using his semen. They compile a list of single women who gave birth in August 2007 and listed the fathers as unknown. Dobson looks through the list to rule out names, and eventually spots one of interest: Chloe Kelcher, who was a juror at Ryan's trial. They then find a death certificate for Chloe's baby with Ryan.
Dobson and the BAU go to her address and find Ryan's body hidden inside a makeshift shrine. They then track her down at the house of Dobson's accountant, Faye Landreaux, who she plans to kill. Just before Chloe is about to kill Faye, she is suddenly distracted with lights and Prentiss reading letters that Ryan sent to his other female fans, while Morgan sneaks in via backdoor to get Faye out. When she realizes this, Chloe eventually chooses to step out of the house and aim a revolver at Dobson. He is forced to shoot and kill her, aggravating Hotch's unrelated ear injury in the process. He and Prentiss investigate Chloe's body, and find that she had punctured herself beforehand in the same way Ryan did to his victims, as a final tribute to him. The next day, Dobson and Sela thank the BAU for helping them and give them some food they cooked, for the plane ride back to Quantico. Dobson acknowledges having to deal with the past before finally moving on, before shaking Hotch's hand and leaving.