The deaths of Toronto billionaire Barry Sherman and his wife Honey in mid-December were a targeted double killing, Toronto police said on Friday.

Det. Sgt. Susan Gomes, of the homicide squad, said thousands of hours of investigation have led police to that conclusion.

“I believe in the six weeks of evidence that we’ve obtained that they were targeted,” Gomes said. “Honey and Barry Sherman were found deceased in the lower-level pool area, hanging by belts from a poolside railing in a semi-seated position on the pool deck.”

Barry Sherman, founder of Canadian pharmaceutical giant Apotex, and his wife, both in their 70s, were dressed, police said.

Related: Homicide detectives now probing billionaire couple’s death

Autopsy results revealed they died by “ligature neck compression,” Gomes said. However, it was initially unclear whether the couple died by double-suicide, homicide-suicide, or double-homicide, leading police to classify the deaths as “suspicious.”

“Facts guide our focus,” Gomes said. “Conjecture and speculation have no place.”

Police, responding to a 911 call, found the bodies on Dec. 15 in their three-storey north-end home. For the past six weeks, investigators have been scouring the home, which was only released Friday morning to the family.

“There are no signs of forced entry on all access points to the home,” Gomes said.

Related: Private investigators to probe Sherman’s deaths

The Sherman family, upset by media reports on the investigation, hired their own team of investigators but Gomes said contact with the relatives has been consistent and ongoing. She said she understood their concerns about the pace of the highly complex probe.

“For them, it’s been difficult to balance their patience with their frustration with us and our investigation, not unlike any other family who has suffered such a sudden and profound loss,” Gomes said. “They have been understanding, co-operative and hopeful that this investigation can give them some answers.”

Gomes refused to discuss suspects, but outlined some of the evidence police have gathered from the home, a second Sherman property and Apotex. Items include 2,000 hours of security video from commercial and residential properties.

Investigators have taken 348 “investigative actions,” obtained 20 judicial authorizations and search warrants in what Gomes described as legal and challenging that so far has resulted in the seizure of 150 bulk or packaged items.

Colin Perkel, The Canadian Press