I just watched this for this first time since i was a wee lad, it was as good as i remembered it. One thing i didn’t get though was why the urgency in retiring the replicants when they were going past their expiration date (quite soon apparently) on their own soon enough?
Weren’t they already killing people?
Yes, but, ironically, only because they were just randomly murderous and becaue some people showed up to find them. Yeah, it is a plothole.
I assumed it was some kind of “as an example to others” deal, but indeed the movie’s plot is somewhat implausible.
In any case, hadn’t they killed 23 people in their original escape, according to the briefing Deckard gets? Plus the movie opens with Leo putting Holden on life-support.
I don’t think it’s referenced in the movie (been awhile since I’ve seen it), but couldn’t at least part of the reason be that Tyrell knew replicants might track him down, whether to kill him or to look for a way to extend their life (Batty did track him down, IIRC).
So - on that basis, and given that the Tyrell Corp. is huge (think Microsoft) and probably has immense political/business pressure it can bring to bear, maybe Tyrell influences the police dept. proactively? He hears of an escape, he goes to the power brokers he knows and says “might be worth your while to ensure that these replicants are eliminated, post-haste”.
Just because they’ll self-destruct doesn’t mean they can’t do a significant amount of damage before that date.
But yeah, there’s probably not too much point in chasing once you get to the 1 hour before shutoff mark.
they werent machines with an internal clock, its not like they turned off exactly 4 years to the second after activation, think about the kind of destruction Batty could have done had he decided to go on a killing spree of the general population, hell think if they had all decided to do it as a team?
you wouldnt take chances like that,
I don’t get it. If Deckard had gotten to Batty a little earlier then Tyrell would be alive. And then there’s Sebastian and Chew. I.e., he wasn’t urgent enough.
Seems quite plain to me.
The opening crawl says quite clearly that any Replicants found on Earth are to be killed by Blade Runners. The law doesn’t care if they’re going to dissolve in a pile of goo any time soon or not, they’re to be “retired” at the earliest possibility. Letting them run around is akin to not pulling over a speeder because you know that he’s going to have to slow down sometime.
I seem to recall replicants were designed for dangerous off-world work and weren’t allowed on earth. The state of the technology was that they were extremely intelligent and dangerous children. A replicant that went rogue was defective and dangerous.
Of course, what I find odd is that Deckard reviews the tape of the Holden/Leon interview, in which an address is clearly stated, and then goes to check it out all by himself. He didn’t even have to push aside any police barricade tape - nobody had yet bothered to check this out. Not even Gaff, who would run into skin jobs later in his career and probably wish he was better at spotting them.
In addition to the above points, I believe the replicants had come to earth to try and uncover a way to increase their longevity. If they discovered this before their regular expiration date, the problem would no longer solve itself. 
This, for me, is one of the worst changes from book to screen.
In the book, you got paid a bounty for killing a replicant. Some paid higher than others. Deckard was broke and he really wanted the score so he could buy a electirc (fake/robot) sheep to impress his wife and neighbors.
Wait seriously? A sheep?
Yup. The film doesn’t follow the book all that closely*. A scene from the book that should have been in the film has one of the replicants (Roy?) pulling the legs off a (real) spider that Deckard has found and kept in a jar - pretty much all animals on earth have been wiped out so the spider is really something special - it shows the replicants in a much less sympathetic light than the film, where they just kill people.
- this is an understatement**.
** so is this.
What urgency? We see Deckard’s work as urgent because he is the focus of the film and it’s work that is important to him. But really, put this in perspective: if a big city puts one guy on a law enforcement task what does that say to you about how important they see it as? It’s not as if they set some gigantic taskforce onto it. Heck, as Bryan points out, they were sloppy as hell. Barely interested.
To me, the authorities have to make some sort of effort to go after these replicants because they have killed and because the law’s the law. But they do so in a decidedly half assed fashion, which fits perfectly with them not being too worked up about it, quite possibly for the reason you identify.
In the book, animals have been all but wiped out. Having a real live animal is a huge status symbol for human beings, and so Deckard and his wife really want one. Of course, it’s a lot cheaper and easier to get a synthetic animal -a robot sheep or goat, and none of the neighbours would really be able to tell the difference but then that wouldn’t really be the same, would it?
The huge difference between replicants and humans is the sense of empathy towards animals. Replicants attach no importance whatsoever to animals and will happily while away an hour or so torturing an animal to death. It’s not because they’re bad, it’s just the way they’ve been created. This is why the test for replicants includes a lot of questions about animal cruelty -replicants can try and fake concern, but they simply can’t fake the instant human reaction to hearing about an animal being abused.
The irony of the book is that, for all the sentimental importance they attach to animals, the humans lack all sense of empathy with the replicants themselves, animal-obsessed Deckard being the prime example.
This is what I figured as well. Deckard asks why they’ve come to Earth again, why the Replicants risked it. The chief tells him that he’s the one that should figure it out. I always had a sneaking feeling that Tyrell wanted them to come back, but that being killed wasn’t quite in the plan. Whenever I think about that, I discard it, because Tyrell is supposed to be thinking about this kind of shit.
They reference this a couple other ways–“Is that a real owl?” “Of course not.” Also most of the pivotal Voight-Kampff questions involved interactions with animals. People didn’t fare too well in the war, either–that’s why Sebastian had that entire hotel to himself.
There’s another goof in the setup, though. Bryant gives Deckard a briefing and says how many replicants there are, but he gets the count wrong… He says there were six, and one fried himself trying to get into the Tyrell Corporation. We saw Batty, Pris, Leon, and Zhora. #5 is crispy now. Where’s #6?