Transcript for Toronto police hunt the killer of billionaire couple

a prominent billionaire couple found dead in the basement of their mansion. The high-profile killings rocking Canada. With Toronto police saying it appears to be a double homicide. Here's ABC's erielle reshef. Reporter: Tonight, the mystery deepening behind the double homicide of one of the world's richest couples. I believe that in the six weeks of review of the evidence that we've obtained that they were targeted. Reporter: For the first time authorities now saying publicly billionaires honey and Barry Sherman were sought out and slain in their home. The two found hanged on the pool level of their sprawling $7 million mansion. The cause of death for both shermans was ligature neck compression. Reporter: Police revealing there was no forced entry to the property. The bodies reportedly discovered in December by a real estate agent preparing for an open house. Authorities keeping a tight lid on any leads. We haven't developed any suspects outside of understanding that people or a person is outstanding for this offense. Reporter: And tonight, detectives still coming through a mountain of evidence. More than 120 witness statements, roughly 2,000 hours of surveillance footage. Two residential properties belonging to the shermans have been searched. The primary Sherman residence is a three-story family dwelling of a size warranting six weeks of searching. Reporter: Barry Sherman, amassing a multibillion-dollar pharmaceutical empire. Police now piecing together who would want him and his wife dead. The Toronto police department aren't mentioning any possible motive. Tom. The mystery deepening tonight. Turning now to the weather and the January thaw, warming

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