DNA Clears Murdered Widow's Son—and Leads to the Real Killer's Arrest

On a quiet summer night in 1991, a brutal killing in rural Delaware seemed to defy explanation. A 70-year-old woman was found stabbed to death in her bedroom, and her son gave investigators a story so strange that they believed it had to be a lie.

Dorothy Donovan was twice widowed and the grandmother of seven. She lived in a close-knit farming community where people knew one another and often didn’t even lock their doors, according to detectives who worked the case.

On June 23, shortly after midnight, that sense of safety was shattered when Donovan’s son, Charles Holden, arrived home and spotted a suspicious-looking man outside the house he shared with her in Harrington, a small town roughly 17 miles south of Dover.

Holden drove to a pay phone and called police. When officers reached the farmhouse, they found Donovan dead in her bedroom. She had been stabbed repeatedly in the chest and face. Blood was spattered across the crime scene, and there was no sign of robbery.

From the start, the case centered on Holden’s account of what happened that night. He told investigators he had encountered a hitchhiker while stopping for a hamburger after work. According to Holden, the man asked for a ride to a nearby town. Holden agreed to take him part of the way, but when he stopped and said he would go no farther, the man became angry.

Holden said the stranger grabbed a screwdriver from the floor of the truck, threatened to kill him and fought with him outside the vehicle. He eventually drove off, leaving the man behind. Then he spent about 20 minutes driving around before returning home only to see the same man wandering around the property.

To investigators, the story seemed hard to believe. Detectives did not trust Holden, especially after he refused to take a polygraph. They also had reason to look at him closely: Donovan had recently taken out an accidental-death insurance policy naming Holden as the beneficiary, and he was dealing with farming debt at the time.

“He was certainly taken [aback] by my accusation that he had something to do with his mother's death,” Michael Warrington, a retired Delaware State Police detective who worked the case, told the TV series Forensic Files. “But I felt that's the way the interview needed to go, because it just didn't seem logical or likely that the events that he was describing actually took place.”

Still, the physical evidence complicated the case. Investigators found a bloody palm print on a railing and blood on a light switch inside the house that did not belong to Donovan. However, the print also did not match Holden’s hand.

Witnesses later helped corroborate part of Holden’s story. Police found people who had been in the parking lot where Holden said he had met the hitchhiker, and they confirmed that a Black man was there looking for a ride and got into Holden’s car. From Holden’s description, investigators also developed a composite sketch of the man.

At the time, detectives suspected Holden may have still been involved and possibly hired someone to kill his mother.

The case remained unresolved for more than a decade, but Delaware State Police had preserved the bloodstain found on the light switch. By 2005, advances in DNA technology allowed forensic analysts to upload the blood evidence into the Combined DNA Index System (CODIS), a national database used to compare forensic profiles against known offenders and other casework, Jamie Armstrong, CODIS administrator for the Delaware Department of Forensic Science, tells A&E Crime + Investigation.

“If there are consistencies within the two profiles, then CODIS associates the two and it returns a match,” Armstrong says. “We go through a confirmation process to ensure that the profile from that convicted offender matches that of the casework profile. Then we release the personal identifying information to law enforcement as an investigative lead.”

Law enforcement agencies are then able to secure a warrant for a DNA sample from the suspect, Armstrong adds.

The DNA from the bloodstain pointed to Gilbert Cannon, a career criminal who had been living in Delaware at the time of the murder. Cannon had served time for drug and robbery offenses, and police eventually tracked him down at a girlfriend’s home about 40 miles from the Donovan farmhouse.

At first, Cannon denied involvement, but after investigators confronted him with the evidence, he told the truth. Cannon said he had been high on cocaine the night of the murder and was looking for more when he ran into Holden at the fast food restaurant. He claimed Holden agreed to give him a ride, but the two got into a fight when Holden refused to take him all the way into town.

Cannon said Holden eventually drove away, leaving him on the road. He said he then walked past several houses looking for a place to sleep, found Donovan’s home and broke in through the back door. Once inside, he woke Donovan and panicked because she could identify him. He grabbed a screwdriver and stabbed her to death.

Investigators also compared Cannon’s fresh palm print to the bloody print found at the scene; it matched. For detectives, that was the confirmation they had been waiting for.

Steve Greenberg, a Chicago-based criminal defense attorney, tells A&E Crime + Investigation that the Donovan case is a reminder that DNA can be both powerful and misunderstood.

“DNA can be a sword and shield,” Greenberg says. “Jurors hear one in a trillion and think that means it has to be the defendant. But it can also exclude a defendant.”

Greenberg added that police and prosecutors often develop a theory early and then refuse to let go of it, even when the evidence points elsewhere. “The law is like a physics experiment,” he says. “For every action there is a reaction. Unfortunately, so many prosecutors and police dig into a theory and then want to be right and win at all costs.”

In the end, the evidence told a story investigators had not been willing to accept at first. Holden’s account of a violent hitchhiker was true. Donovan’s killer was not her son, but it took DNA and the palm print matching Cannon to finally identify him more than 10 years later.

Cannon pleaded guilty to first degree murder and was sentenced to life without parole in 2007.