An innocent person can lie as well as a guilty person. If Jeremy has said that he saw a silhouette at the window, for instance, then clearly that is almost-certainly a lie, but it does not follow from this that he is guilty. We're talking about somebody who has spent most of his adult life confined in high security prisons. If he is actually innocent, then he will be desperate. Much of what he says needs to be taken with a pinch of salt.