There's a reason why we're not being told very much about Anthony Esan.
Probably more than one, but they're not what you're implying.
The first, and main one is that pretty much everything beyond his name is a matter for his court appearance in a month. Others are what do you think we should know? Stabbing a REME Colonel is a weird thing for a terrorist to do, as Medway isn't short of easier, messier(an important consideration for terrorists), higher profile targets, and he'd have stuck around to have a go at the other soldiers arriving from their homes, barracks and school. Many of them are Gurkhas, and you'd have to special kind of nutter to attack
them with knives

.
The immediate determination that he isn't a terrorist was made by people with more data than us. Finally, if he is a nutter with a bag of kitchen knives, then he's just a nutter with kitchen knives and there's little more to know.And no, I'm not going to contact my friend who lives in the same road just to satisfy your prejudices.