The 203-296 is an area code for Connecticut. Everytime he post a number whether its changed or not the area code stays the same. Looking it up even more the 296 tracks back to Bridgeport. So, I am assuming his from around that area. If someone could just get a name..
The only problem I can see is this is not actually a cell number but a google voice number. However he would still have to connect his cell phone or his land line in order to create a google voice. Im sure theirs a actually way to get his real number. The we can contact the police.