Winkles claimed that he had killed a total of 62 people during his lifetime, but no other murders were definitively corroborated, and he died awaiting execution in 2010.
On September 12, 1981, Winkles was arrested in Pinellas County on charges of fraud for selling forged documents, but was released from custody after posting bail.
On January 6, 1982, Winkles entered a real estate agency based in Seminole County and, using the alias 'David Longstreet', asked the 28-year-old saleswoman Donna Maltby to show him some of the homes for sale.
On the early morning, Winkles called the agency and said that his car had broken down, requesting that Maltby pick him up from the parking lot of a hotel he was staying at.
Winkles had intended to drive Maltby to Tampa, where he had a rental apartment, but lost his way in the fog and had to stop at a gas station in Pine Hills.
Winkles was arrested soon afterwards and brought to the police station, where he tried to claim that he had seen Maltby stealing $8,900 from her agency's cash register, but no such money was found.
He then tried to convince the investigators that he had no intention of abducting or assaulting her, but a search of his vehicle turned up drugs, a set of handcuffs, rope, duct tape, bottles of alcoholic beverages and a briefcase containing women's underwear that did not belong to Maltby.
According to the investigators, the items found during the search were likely tools used in abductions of other victims, with the women's underwear possibly being fragments of their clothing which was kept as a trophy.
[5] In August 1983, forensic analysis identified the victim found in Citrus County as 39-year-old Margo Delimon, a real estate agent who went missing on October 3, 1981.
As both Delimon and Maltby worked in real estate agencies, investigators suspected that Winkles kidnapped and murdered the former due to the similar modus operandi.
[11] During a conversation with representatives of the Prosecutor's Office, Winkles offered a deal in which he would plead guilty to the crimes in exchange for not receiving the death penalty, but this was denied.
Over the next several months, Winkles participated in various investigative experiments and spoke at length about his crimes, but was unable to remember where exactly he had dumped Graham's body.
He then stole $20 from her wallet and stabbed the tire of her vehicle, before driving her to his grandmother's house, where he sexually assaulted and sodomized her for four days.
He claimed that Delimon remained calm and did not attempt to escape, even when he suggested that they take a walk on the beach and visit a fast-food restaurant for dinner.
According to his testimony, after completing the trip, they returned to the vacant house, where he forced her to take a large amount of sleeping pills that caused Delimon to overdose.
This had a negative effect on his physical and mental health which ultimately led him to admit responsibility, stating that he had begun to feel remorse and urgently wanted to contact the victims' relatives to ask for forgiveness.
They provided various reasons for the appeals, ranging from mitigating circumstances such as his childhood abuse and his current health problems to his reputation as a model inmate.