Could the perp have a thing against the former Utah Jazz CEO and took it out on the mother-in-law perhaps thinking she was actually his mother?, speculation, imo.
2018
Crimewatch: the Murder of Sherry Black
“She had been brutally beaten and murdered,” Rosie Rivera, Salt Lake County Sheriff says.
''Rivera says the crime did not appear to be well-planned.''
Police believe the killer left a brown imitation Armani Exchange belt at the scene of the crime, though they don’t believe it was used in the murder.

Police believe the person who killed Sherry Black left this belt at the crime scene.

Police say this imitation Armani Exchange was left behind by the person who killed Sherry Black.
''Investigators were able to collect DNA, finger and palm prints as evidence and enter them into a database. Because of that DNA, they were more recently able to
release a composite of what the suspect might look like, in hopes it would help lead to an arrest. The phenotype is not meant to represent an exact depiction, as there are variables within DNA.''
''Black was the mother-in-law of Greg Miller, the former CEO of the Utah Jazz. The Miller family is providing the $250,000 reward in the case.
Again, if you have information about the murder of Sherry Black, contact Salt Lake County’s cold case detectives at
385-468-9816.''