Oh, My Gosh ! Internal thief in my office !

This morning i came back to office as usual, and wonder that a colleague was crazy looking around for company testing phone . That is Nokia 6233,which she has been lock in her drawer before she left yesterday night. Actually most of the times , beside the customer support team keep those company fons , also the technical side colleagues will need to borrow it sometimes too. So tat gal wonder is tat someone took it urgently at night and forget to inform her...( because technical ppl they knows the key is put on where ) After tat , she sent out an email to everyone request for the fon back. Who knows no one get feed back to her. Then she start suspect the fon was been stole by internal colleague.Because yesterday , after she left the office, the other customer supports team leader was still there to rush something, then a new technical guy came over n ask for a Nokia 5700 test fon to do testing. So the head of CS was as usual take the drawer key from the usual place they keep the key , n open the drawer pass the Nokia 5200 to him. That time the Nokia 6233 was still there, as the head was very comfirmed she saw the fon before it missing. So the head of CS left around 7pm something, tat time office almost empty, except techincal side of ppl. Thats usual seeing technical ppl staying late in the office, to do support.
Anyhow, CS was suspect someone .. tis company nvr happend such missing things case, until recently came in few new staff , one of it is tat technical guy who borrow the Nokia 5200 before the Nokia 6233 is missing ..... ..... ..... wat do u think? i actually also suspect is him, but we hv no prove, so we cant say anything. Just can be careful all the times , take care of our own properties all the time... Feel so sien , cz the peaceful working enviroment , now become not secure anymore. My wallet , my cell phones even my laptop also need to protect it all the times in the office .. :( * sigh *