In my brief investigations, it appears he was ONE OF THE GOOD GUYS that was suicided or compelled to do so for what he knew. I hope we learn why this occurred.

I found these statements written about him:

Thomas Kingston Suicide: Associating With A Royal Family Came With A Price?

"...those that knew him well, described him as a “very, very, very” committed Christian. At uni, he was even known as “Christian Tom.”

"Tom is one of the most remarkable people I have ever worked with and I would have him back at my side tomorrow, if he would come,” Canon Andrew said of Kingston while he was still alive. “Tom has a fierce determination to make things succeed and great insight into what makes humans tick, both good and bad. He uses those to see beyond the impossible and get through to the other side.”

"In light of his tragic death, Canon Andrew told The Telegraph: “We survived several suicide bomb attacks [...] We were regularly caught up in IED [improvised explosive device] attacks. Cars would blow up in front of us and we would just move on. We were always together and had 35 armed guards at all times,” recalled Canon White."

“The thing about Tom was he was never scared. Whatever I asked him to do he would do it with a big smile on his face in the middle of a war zone.”

"Following on from his time at the Foreign Office, Kingston joined the Iraqi Institute of Peace as a project officer from 2003 to 2006. The Times reports that Kingston “developed a reputation as a talented young diplomat and a devout Christian” during his time there, and worked tirelessly to help Iraqi Christians rebuild their lives in the wake of Saddam Hussein’s reign of terror."

"One close acquaintance told the newspaper: “We are so upset about the news, everybody loved him. He was kind, charming and thoroughly decent and one of the last true English gentlemen. It is beyond tragic and so hard to get one’s head around.”

"The local sub post-master added: “We are all so sad to hear the terrible news. They are a lovely, gentle family who do a lot for the village and the church. They are a big part of the local community [...] Thomas popped into the shop a lot, he would come by every so often. I last saw him a few months ago. He was a very gentle soul, just like his father. Everyone is in shock, it’s really sad and very fresh.”