It appears that the entire case against Cannan is based on anecdote from one informant. If we look at the timeline of Cannan coming into the investigation, it offers an interesting picture.
In 1986 SJL disappears - a week over 37 years ago, poor thing. In 1988 Shirley Banks is abducted and murdered. In 1989 Cannan is interrupted trying to rape someone else, and in 1989 is convicted for this. After that trial, right away, it starts to be suggested that he looks a lot like the Mr Kipper sketch. For my money, on that basis
Shakin' Stevens should also have had his collar felt, but let's park that.
Eleven years then go by, during which there is no movement or development at all. Then suddenly the police start getting all interested in Cannan. They begin the first of several searches at sites supposedly related to Cannan.
The pressure to do this came from Diana L, but the proximate source of Cannan-related information was this character Joseph Taggart (hereafter JT). JT was a cook in the pre-release hostel Cannan was held in early in 1986 - I'm not sure whether he was a cook
in the hostel, or lived in the hostel and cooked in the prison, or cooked elsewhere. Whatever; Taggart was a lifetime habitual thief and fraudster who by 1999 / 2000 was claiming to have been an associate of Cannan's thirteen years previously.
JT was apparently now giving the police all kinds of stuff on Cannan. For example, the supposed BMW, the supposed cunning use of his prison nickname (with at least three different origins), and Cannan's habit of poncing around fancy Fulham wine bars were all "corroborated" by JT. Yet JT also seems to be the source of the claim that JC frequented the PoW, which wasn't a fancy Fulham wine bar at all, but a scruffy pub in Putney, and somehow JT remembered its name thirteen years later. You also wonder how JC hung around the pub and nicked her diary if she knew him by sight, and why, as a cheque book fraudster, he didn't steal money from her.
Unfortunately, all this seems to have been stuff JT could simply have read about JC in the newspapers ten years before (at which point JT was out). Even more unfortunately, the thing JT didn't seem to be able to remember, even though he was supposedly JC's mate, was JC's movement the day SJL disappeared, or where he had buried her. That is, JT conveniently couldn't remember anything that would lead to any actual evidence against JC.
One is therefore left wondering what JT was up to, and whether all this stuff came out because he needed a deal with the police. They clearly bought his story. The reason the nonsensical tripe about people remembering stuff from 14 years ago is wheeled out by JD et al as part of their case against JC may be because their real case is based wholly on the word of a lifetime felon. He didn't come forward for ten years, gave them nothing that could be verified and is by any measure 0% credible. They can't really say that out loud, so perhaps the appeals for more witnesses came about because they needed others, more plausible than their snitch, to verify JT's account. As a witness or even informant, he was worthless.
For JT to wait ten years, he can't have been acting as an upstanding concerned citizen. He must have needed something from the police. What he had to proffer in return, but carefully, was information about SJL. If he gave them too much accurate stuff on JC, he risked being connected with her fate himself. Too little, and it would look like he had no information at all. What he seems to have given them is what they wanted to hear, but with absolutely no concrete leads to where her body is. The police have been digging in all kinds of random spots with no luck, because JT either didn't know or was not going to tell where she really was.
For my money she's under a floor somewhere in west London; whether JC was involved remains impossible to say.
MOO...etc