In the poem 'About His Person', how does Simon Armitage construct identity?

In his poem 'About His Person', Simon Armitage constructs the identity of the titular 'Person' through describing the objects that surround him. The 'giveaway photograph' in his wallet gives away, so to speak, the sense that he has 'stashed' away something close to him; the double entendre of 'heart' in the following line suggests this is a romantic attachment. Armitage also uses wordplay to hint at an unseen act of violence, using a lexis of words such as 'slashed', 'stopped', and 'beheaded'; this fits with the tone of a detective investigation that pervades the poem.However, Armitage also creates a sense of absence and suggests that aspects of the man's identity are inaccessible to us. The note of explanation is 'beheaded', a suggestion that the key to this puzzling scene has only partially survived. The couplet 'beheaded, in his fist./A shopping list' uses rhyme to highlight the dissimilarity between the suggestion of violence in 'fist' and the mundanity of the 'list', suggesting that such remains do not give us enough access to this man's true emotions. Indeed, 'That was everything' could be read as a sign of meaning, or as an acknowledgement that the clues have run out without the whole truth having been revealed.