"Day of the Viper" is an episode from season 1 that looks as if it came from season 7. What I mean by that is that the story idea is poor and the murder weapon is VERY improbable and unlikely to actually kill....and such ridiculous plot ideas are what you usually see when a show has run its course and the writers are running out of good ideas.
When the story begins, a rattlesnake jumps out of a man's bar and bites him....killing him in seconds. Soon Barnaby Jones is hired to determine if this was a freak accident or the result of foul play.
Just because a rattlesnake is left in someone's house doesn't mean the snake will try to bite anyone. And, if it does, determining WHO will be bitten is far from certain. And, if a person is bitten, they nearly always survive. If they do die, they die hours later. But in this episode, the snake bit an intended victim AND he died only seconds later....which really makes no sense at all...especially because they show the guy panicking (which would speed up the venom getting into the system) but the victim was an expert rattlesnake wrangler! In other words, the writer really didn't know what they were writing here and the episode exploits folks' fear of snakes. And, it's obvious the writer did zero research before writing this.
In addition to badly handling the snake angle, the show also was very poor for a few other reasons. The biggest problem was that the killer was OBVIOUS....and every time you see him, he acts incredibly guilty. Another problem, though much smaller, is the checkers scene--which was cliched and dopey. As for the finale, it was also just plain dumb. All in all, an incredibly disappointing episode....probably the worst of season 2.
By the way, this episode features Vince Van Patten....the son of Dick Van Patten. He was also a professional tennis player as well as an actor on many 70s TV shows.