Silent Witness

Description for SILENT WITNESS by Collin Wilcox:

Millionaire artist Janice Hale hires actor-director-private eye Alan Bernhardt to investigate the death of her sister, Connie, supposedly killed by an intruder at her home in the California wine country. Janice is convinced that Connie was murdered by her husband, Dennis Price, for her $25-million estate. The only witness to the crime is Connie's seven-year-old son, John, but Dennis won't let Janice talk to him alone. More important to Janice than proving Dennis's guilt is the welfare of her nephew, whom she may want to adopt.

This is #2 in An Alan Bernhardt Novel.