Why do you think he was murdered?
It's the old Frankenstein trope isn't it? The created creatures always end up revolting and cause a ruckus.

Dr. Ruth appeared to be in his 50s, and the whole movie appears to be set in 1980 or so. Which is why I was surprised when Ruth told Vale that he had founded Biocarbon in 1942. That's almost 40 years ago! Unless he started the company as a teen not!
Dr. Ruth's actor was in fact only 52 in 1980, when this was filmed.

He was acting under orders from Darryl Revok who said during their secret train station meeting, "If Ruth finds out anything, anything at all.. kill him!"
This summer, things are gonna get HOT!
That's High Ozone-depleted Temperatures, people >:(!