What you said may be true in the sense that he's a deceased character, however this is not a rule set in stone across various wikis. Take The Walking Dead's wiki by example, even if a character has died it they are still written with "is" rather than in past tense as "was".
I've seen other Wikis that continue to refer to a character with "is" rather than "was". I know they're dead now, that fact isn't disputed but it doesn't change the fact that they are a character on the show. That standing isn't effected by their living status and that's how other wikis operate.
However, your stance is backed up by other Wikis choosing to use "was" for deceased characters. Example being the Buffyverse Wiki, where deceased characters are referred to with "was" indicating their profession and role in the series. I've found examples in NCIS and Resident Evil as well.
I'll bring this up with the admin...back when the series was still active there was a dispute between "Is" and "Was" there as well. It's been some time so I forgot how we ended up ruling.
It doesn't change that he is a character. but he is not a dedective anymore because he died and dead people can not act as a dedective. Therefore it is a must to use "was" instead of "is". There doesn't have to be a rule they are dead after all and if you check again, you see that in the walking dead wiki and most of this wiki they use "was" instead of "is".
I pulled up multiple articles in my search and the initial opening all used "is" for dead characters. However what they said was "is the former" rather than using the term "was". Either way is fine...I just don't feel it's incorrect to say "is" nor am I disagreeing that "was" is correct.
Unrelated and this is just a minor thing (not to be rude by pointing it out) but it's spelled detective, not dedective.
Well sorry about dedective that, it's just my mother language and thanks for pointing it out. I believe sometimes "is" could be correct too if you are saying "he is ...'s brother" or etc. But in those sentences in the Doakes page it felt like "was" the correct one. I did pull up articles too in this wiki too and almost all of them is with "is" instead. Anyhow, there no point to continuing this conversation now. It's best to wait for the reply of your message.
It's alright, I understand language differences can result in different spelling. I just wanted to point it out in case future contributions were altered for the English spelling of some words.
Chances are those articles with "is" resulted from 6 plus years ago while I was an admin here along with a few others and had to build the Wiki up from scratch. I'm fine with changing things to "was", I just want to be on the same page throughout the whole wiki on which is best used.