A guy came into my shop with a laptop in bits and asked if i wanted it for 40 quid,?

considering the laptop was in bits (back off, most of the internals out) and it was filthy i thought it was a reasonable offer, 20 mins later a guy came into the shop asking if i had been sold a laptop, told him i had, he claimed it was his and his house had been robbed, i asked him to prove it and when i put the thing back together and it powered up he showed me items on it that where his....i then got the police involved and as a gesture of goodwill gave the lad his laptop back, (cleaned and flaming repaired as well). the police are now saying i could be charged with handleing stolen goods, i didnt know it was stolen, and 40 quid for a laptop thats in bits and filthy wasnt an unreasonable price. can they do this? the guy who came in and asked for his laptop reckons it was his mate who robbed him and he saw his leaving my shop as he drove past, thats why he came in, even the police think they aint telling the whole story, yet its me they are getting heavy handed with. i have never been arrested, never been in trouble with the law and never been investigated, i even deal with police within my business.....just seems a bit strange that its me they are getting heavy with as the thief is doing the silent act in interview!!!