I would like to pose this question to people. Hypothetically, if the police found blood drops or stains or an attempt to clean one's car boot of some stain, which would look suspicious in this case; if that car was Borce's, and if you were on a jury, and if the police were alleging Borce killed his wife, disposed of her body, and there was no body or handbag to be found because, as the cops claim, he is not confessing as to where he stashed them. Then would people convict him? It is circumstantial. The boot looks to be freshly scrubbed with some heavy duty detergent, but a few specks of Karen's blood are still present, ones that he missed.
The police further claim that the house was in Karen's name, Karen was going to leave him, and the business wasn't doing so well. Obviously the defence would dispute these claims. Without Sarah saying anything, would people convict him of Karen's murder? I personally would not, i don't think. It seems a bit too flimsy for my liking. Although it is sus as hell, it's also a bit flimsy for my liking. They need more evidence than just this.
I posed this hypothetical because it is interesting and i keep on thinking about the cars at forensics, and maybe they are awaiting toxicology reports, which seem to take weeks.