Actually like 'Taggart' very, very much indeed. Loved it even at its best. If more the earlier episodes (so the Taggart and early Jardine years) than the later years, when the lengths became shorter in particular the show felt well past its sell date unfortunately. "Cause to Kill" was not one of my first 'Taggart' episodes watched when first getting into the show (back when the later Burke episodes aired in two parts on weekday afternoons), instead it was seen a couple of years after the show ended.
"Cause to Kill" is really not one of the best 'Taggart' episodes. There are worse episodes of the show, since and even before, but the show was really starting to run out of ideas at this point (or at least that's how it felt) and that tiredness and predictability can be seen in "Cause to Kill". An episode that has a good deal of good things but somehow it felt lacking and somewhat bland. Calling a 'Taggart', one of the grittiest shows of the genre, bland is not a compliment.
There are as said good things with "Cause to Kill". It is well-made visually, with the usual grit and moodiness in the photography. The scenery is both picturesque and unforgiving, though Glasgow's portrayal is indeed more favourable than it is in most episodes. The script intrigues, pulls no punches and there is some entertaining banter within the team. The team interaction is always cohesive and there is never a disconnect, with some nice banter and also intensity.
Development-wise, all the lead characters have come on a long way (though Jackie, the longest serving team member, was always interesting and a bright spot). The cast all give reliably good performances.
On the other hand, "Cause to Kill" lacks tautness and tension and has too many recognisable plot and genre tropes stitched together, with twists being too few. Which makes it feel tired and predictable. The denouement especially is agreed obvious far too early, the motive is old and doesn't take a lot of figuring out and the number of suspects are too few for the identity of the killer to be shocking.
For a plot synopsis that gives the impression that things are not what they seem, this is pretty ordinary stuff. Not at first within the episode, but when talking about visual media in general there is nothing new. While the supporting cast are game, the characters are too one-dimensional and too familiar. The music is again, apart from the main theme, at odds with what goes on and sounds twenty years out of date.
In conclusion, above average but could have been a lot better when you see how great 'Taggart' can be. 6/10