But it was their similarities that convinced police to do something they don't often do in homicide cases: Offer a sizable reward for helping them catch the killers.
San Bernardino Police Chief Robert Handy on Monday announced $30,000 in rewards for information in the deaths of Mary Beth Blaskey, Josephine Frances Kelley and Wanda Lee Paulin - three elderly women who were found dead after their homes were burglarized.
"Any and all information is important," Handy said at a news conference Monday. "It may help us put together the puzzle to help solve these cases."
That puzzle has three common pieces: elderly women burglary and murder.
But in the seven years after Kelley's death, stronger links just aren't there.
Lt. Paul Williams said that despite the similarities in the cases, detectives do not suspect the same people committed each crime.
"There's no physical evidence that links the cases together," he said.
Police hope the rewards - $10,000 for information in each case - lead to some answers.
San Bernardino police generated a third of the reward money through the police union and the rest from asset forfeitures in drug cases. Officers and the victims' families are also seeking help from Gov. Jerry Brown to add another $50,000 in rewards for each case.
Joanne Ballard, Paulin's daughter, said a campaign she began a week ago has already generated 160 letters that will be sent to Brown.
She described the pain her family has felt since Paulin's death.
Ballard discovered her 86-year-old mother's body in their home in the 5000 block of North Mountain View Avenue on Dec. 12, 2010. Valuables - including an heirloom wedding ring and a blue topaz ring - had been stolen.
"The shock of finding her is so great, it will remain with me for the rest of my life," she said.
Similar circumstances surrounded the Nov.
The 76-year-old woman's home had been ransacked and her 2001 Lexus ES300 was missing. No suspects have been identified.
"This is a horrible situation, and these people are dangerous," Dirck Blaskey said.
Police found the vehicle abandoned in the northeast part of town more than two weeks later, but no arrests have been made.
Blaskey, a longtime clerk and secretary for San Bernardino City Unified School District, had taken time off work because of illness about two weeks before her death.
Kelley was found dead by her daughter, Susan Hassett, in their Muscupiabe Drive home Sept. 15, 2005.
The 90-year-old woman's hands and feet were bound and her body was lying sideways on her bed, police said.
Police initially arrested Kelley's grandson, Derrick Mitchell Hassett, a day after the killing, but prosecutors rejected the case less than a week later.
"The initial turndown was based on insufficient evidence," said San Bernardino County district attorney's spokesman Chris Lee.
What city authorities are sure of is that burglary is an issue these days.
"Our burglaries are up significantly," Handy said.
Burglaries in the city were up in 2011 and again in 2012, he said.
"We'll have a rash in one area, then in another," Handy said.
Mary Beth Blaskey
And when police crack down on one area, another area picks up.
Among the areas with an increase is the north side of the city, where the three women were killed, Handy said.
San Bernardino isn't the only city with problems connected to burglaries.
In December, Redlands police Officer Alex Paredes warned residents through Facebook that residential burglaries were hitting the city, and that most of them were door kick-ins.
The burglar knocks on the door and if there is no answer, they pry or kick it in.
"This is a great time to have a large dog watching your house," he wrote on Facebook.
San Bernardino Police Department anonymous tip line - 909-384-5656
San Bernardino police homicide Sgt. Gary Robertson - 909-841-5361
Staff writer Ryan Hagen contributed to this report.
Reach Melissa via email or call her at 909-386-3878. Get the latest crime and public safety news on Twitter @IECrime.