Hallandale Beach Police Chief Dwayne Flournoy also announced in a Wednesday press conference a $51,000 reward for information leading to an arrest in the deaths of Rochelle Wise, 66, and her husband, David Pichosky, 71.
Flournoy said the medical examiner has concluded the couple "died due to asphyxiation," but he would not specify exactly how that occurred.
"The other thing we know from the crime scene, and the science of the crime scene, is that this was not perpetrated by a sole perpetrator," he told reporters at a Hallandale Beach news conference.
"There were multiple culprits in this double homicide. And as we release more details of this homicide, you will find how senseless this murder is."
Detectives have not identified a motive, he added.
The bodies of Wise, a popular former day camp director and educator, and Pichosky were found on Jan. 10 in their winter home in Hallandale Beach.
Wise and Pichosky were scheduled to meet neighbours for lunch, and when they didn't hear from the couple, the concerned neighbours used a spare key to check the home and found the couple inside.
Couple went to Jewish temple, Wal-Mart before death
Police have since put together a timeline tracking the couple's whereabouts on the day before their deaths. Flournoy said Wise and Pichosky were at the local Jewish temple in Hallandale Beach on Jan. 8.
Later that evening, the couple went to Wal-Mart, which police confirmed using surveillance video from the store, the chief added.
On the morning of Jan. 9, the couple spoke to a family member via FaceTime video calling on their iPhone, said Flournoy. On Jan. 10, their bodies were found.
Last month, police released video from a neighbour's surveillance camera hoping to identify a woman seen walking to the rear of the couple's home on Jan. 9.
Hallandale Beach Police said Wednesday they are still hoping to identify this person, but haven't received much information or any leads.
Wise's son appeals for information
Police don't know if this individual is a suspect, but finding the person is "critical to us," said Flournoy.
"We don't know if the person is involved. Perhaps they saw somebody, and they may be a witness. And they may not even know that they are a witness. Because they may have seen someone or seen a car, seen something."
Wise's son Jamie said he was hopeful the reward, offered by private donors in co-ordination with Crime Stoppers, could lead to more information.
"We're just looking for any bit of information. Anything that anyone might know, have seen, even thinks might be out of place," he said. "It could help find the people that did this to my mom and to Donnie ... Call the police, help our family get through this difficult time."
Flournoy said he was "confident" this case would be solved in due course.
"It angers me that someone came into this home and killed these two people who, [from] what we've been able to identify, they have no enemies," he said. "They were nice people. They were enjoying their retirement. They were enjoying their new marriage."Suggest a correction