Federal Bureau of Investigation Special Agent Chester "Chet" Desmond was called out by Regional Bureau Chief Gordon Cole to investigate the murder of a 17-year-old girl named Teresa Banks, who was found wrapped in plastic.
Murder of Teresa BanksEdit
Desmond was in Fargo, North Dakota in February 1988 with other FBI personnel, where he was arresting two women outside a school bus full of children. His car phone rang, Regional Bureau Chief Gordon Cole on the other end in Portland, Oregon. He said that there is a girl named Teresa Banks that had been murdered and wanted him on the case.
Desmond arrived to meet Gordon, who introduced him to Sam Stanley, who "cracked the Whitman case." A woman called Lil came out and danced, Gordon saying she was his "mother's sister's girl." Sam later asked about her dance. Chet said her sour face meant that the local authorities were not cooperative, her eyes blinking meant there was trouble higher up with the law enforcement, her hand in her pocket meant they are hiding something, her fist meant they were belligerent, her walking in place meant there would be a lot of legwork, her being Cole's "mother's sister's girl" meant the sheriff's uncle was in federal prison, her tailored dress meant drugs, and her blue rose meant something he could not tell Sam about.
They arrived at the Deer Meadow Sheriff's station, where Deputy Cliff Howard and the secretary would not let them see Sheriff Cable. Chet then forced his way past the deputy and went to Cable's office. The sheriff insisted that they had the situation handled on their own and did not need the FBI's help, mockingly calling Chet as "J. Edgar." Desmond ordered the files on Teresa Banks, who was a drifter with no loved ones.
He went with Sam to the morgue, where they examined Teresa's body. They found that the cause of death was likely repeated blows to the head from a blunt object. She was also missing a ring. Under the fingernail, Stanley found a small piece of paper with the letter 'T' on it.
Desmond and Stanley left the morgue at 3:30 AM. Stanley asked where they would sleep, and Desmond said that they would get something to eat first. Sam commented that Chet had his own modus operandi and they headed to Hap's Diner, where Teresa had worked as a waitress. They talked to a man named Jack and ask about Hap, who they discover is dead. They asked about Teresa Banks and found out she did not have any friends or companions. He told them to ask Irene. They went inside and spoke to Irene, who said Banks only worked at the diner for a month and was always late. Irene believed she had a cocaine problem. She also said that for three days near the end of her life, her arm went completely numb.
They left the diner later in the morning and decided to go to Fat Trout Trailer Park, where Teresa had lived at the time of her death. Desmond saw Irene leave and thanked her, then said "good morning."
They went to the trailer park, where they met the owner, Carl Rodd, who took them to Teresa's trailer. There they found a photo of her wearing the ring. Rodd brought them strong cups of coffee and an old woman came to the trailer but left when Chet asked if she knew Teresa Banks.
Desmond and Stanley went back to the sheriff's station to get the body, but after Cable refused to hand over Teresa's body, he challenged Desmond, first displaying his ability to bend rebar. They fought, Desmond standing triumphant. Chet then bent rebar in front of the sheriff and taunted the deputy. 
Chet told Sam to take the body back to the Portland while he went back to the trailer park for the "blue rose." He asked for Deputy Cliff Howard's trailer, but went to a mysterious trailer and found Teresa's ring underneath. He reached out for it and disappeared.
Behind the scenesEdit
The Teresa Banks case was originally to be given to Dale Cooper in Twin Peaks: Fire Walk with Me, as portrayed in The Autobiography of F.B.I. Special Agent Dale Cooper: My Life, My Tapes. However, due to Kyle MacLachlan wishing to have a smaller role in the film, Desmond and Stanley were written to take his place in the investigation.
- While not stated in the film, the script suggests that the arrests outside the school bus at the beginning of the film were being made as the driver had been using the bus to transport prostitutes.
- Desmond's initials "C. D." are the opposite of the ones of Dale Cooper, probably done to show how different they are.