This article originally appeared on GameSpot sister site onGamers.com

One year ago today, MIT Police Officer Sean Collier's life was taken inside his police cruiser, allegedly by the suspected Boston Marathon bombers. While Seans' dream was to become a city police officer, many may not know of Collier's passion for video games as a lifelong competitive gamer and fan of esports for more than 15 years. Collier's best friend Brandon Kelly wishes to tell the story of their love for video games, and for each other.

While Seans' dream was to become a city police officer, his passion was video gaming. On this day of reflection, best friend Brandon Kelly would like to pay tribute to his friend by recalling their friendship and the large part video gaming played in it.

Known as Sean 'defX' Collier, Officer Collier met Brandon 'heLiarc' Kelly at Shaesheen Elementary School in Wilmington, Massachusetts at the young age of 4. Born only 10 days apart--January 3, 1986 and January 13, 1986--Collier and Kelly instantly hit it off, going over to each other's houses to play the original Mortal Kombat, along with Yoshi's Island, Contra III, and Mario Kart. Not only did the bond of Sean and Brandon grow together, but also did each of their brothers, and the families of Collier and Kelly as a whole. They considered themselves brothers in every sense of the word.

"I remember playing the original Nintendo when we were really young, blowing into the cartridge to make games work", Sean's brother Andrew Collier told onGamers. "It was something he was really interested in from a pretty young age. It was definitely a big part of him growing up."

While their time playing on Super Nintendo was memorable, Collier and Kelly's true gaming companionship began with PC gaming. Collier was a hardcore Intel fan, running a Pentium 1 166 Mhz, while Kelly preferred AMD, running a similar AMD 166 Mhz machine. Their PC gaming started with Lemmings, Duke Nukem II, Wolfenstein 3D, and WarCraft II.

Collier and Kelly both upgraded their computers; Collier to a Gateway PII 333 Mhz, and Kelly to an IBM AMD K2 333 Mhz. Soon after came the most pivotal game at the time for them, and the one that first led them down the path of competitive gaming - StarCraft.

"Due to his love for Blizzard, Sean immediately picked up Starcraft on its release and first fell in love", Kelly told onGamers. "Sean and I were in the 6th or 7th grade and after we got out of school, we would both go over to his house and switch off playing competitive ladder on his computer. I learned a lot from Sean, his micro skills were unbelievable and no matter what strategy anyone threw at him, he knew how to defend and counter."

"Doing really well in Starcraft, Sean and I joined our first ever gaming clan called Protoss Domination [pD] where we played for the better part of two years. The clan was split into two 'elite' groups of players, and Sean was in the better of the two. He played Starcraft non-stop for years and even still played up until last year with Starcraft II."

Collier and Kelly's love for competitive gaming grew from there with the rise of first-person shooters. "Some people may have heard of this game called Team Fortress Classic. You should have", exclaims Kelly. "It was quite a revolutionary mod that came from Half-Life. Sean and I played quite a bit of TFC together and got really good at it. He enjoyed playing a Soldier/Demo/Sniper while I was Medic/Sniper/Soldier. We started getting really into TFC, had plenty of fun on conc jump maps and eventually joined a team (which I completely forget the name of) led by some kid named 'TriggerHappyGuppy'. We played in I believe it was OGL Open for a season, but fell in love with this other FPS called Counter-Strike."

Playing Counter-Strike was only made possible through another feat of its own: a championship run in the NASCAR game at the time by Sean and his brother Andrew to win new computers to run the game in the first place.

"I remember back then Gateway had stores. The gateway stores had a competition for the then current NASCAR game, where the fastest time trial would win a computer", says Andrew. "Sean and I won that tournament, and that's how we each got our own computer. I had to have been 13 or 14, and he was 15 or16."

GoldenEye 007 had come out by then, and Kelly talks of many nights of split-screen multiplayer. But for many PC FPS players during that era, Sean and Kelly's main FPS attention turned to Counter-Strike.

"We were just trying it out really, and we fell in love with the game", says Kelly. "CS drew our attention almost immediately and we both started playing at the ripe age of fourteen. As we entered High School, we came across another CS junkie who was also a freshman. His name was Zachary 'Hyperion' Mitzan and us three were becoming some very competitive players who were very close in skill which allowed us to push each other to get better."

"We also eventually attended local LANs's when we were 16 and Sean could drive us to BattleLAN / Dream Machine in Danvers, MA. We use to smoke kids as they came through thinking they knew how to game."

"Sean being the leader he was, formed a Counter-Strike team called Elite Assassins (eA). We started off running through pubs and destroying kids like it was our job. Our goal was to see who could be called a "cheater" or "hacker" first. From being pub stars, we ran into a couple of kids in which we expanded the team, by picking up Alex 'Woll' Woll, Vivi, Sabin and EyEdeA."

"With this roster, Sean signed us up for this Cyberathletic Amateur League (CAL). We joined CAL-OPEN and stayed OPEN for two seasons in which I left after the first or during the second because Sean and I would fight like little girls. I moved on to hop into a CAL-MAIN team Pitcrew, Last Breath and eventually Point bLanK (teammates with zEx Titus, yuK` and hickeyyy). Sean continued to successfully lead his team into CAL-im as well as becoming a DJ for an online radio #DigitalRadio on GamesNet IRC. He loved DJing and would host giveaways as well as LMS tournaments.

"He spent a lot of time following his favorite team Team 3D, as well as his favorite player 3D's Sean 'Bullseye' Morgan. His favorite CS video was 'BSL from the Block'."

The gateway stores had a competition for the then current NASCAR game, where the fastest time trial would win a computer. Sean and I won that tournament, and that's how we each got our own computer.

Some of brother Andrew's fondest recollections of Sean's childhood growing up is one that many competitive gamers can relate to through their own personal experience.

"I remember waking up in the middle of the night going to the bathroom, I walked out and you can see the glow of his computer screen under the door", says Andrew. "I would go back to sleep for hours and when it was time to wake up, he would still be there playing."

Collier and Kelly were so close and so competitive that they would fight like "boyfriend and girlfriend", as Kelly puts it. Both of them had to be right, but only one could be the leader of the team. This clash combined with their dislike for the 1.6 iteration of CS--and move to college--called for them to split for a brief period of time.

"We were both just young and didn't like taking orders from each other," says Kelly. "It was better for our friendship. Sean and I both went our separate ways and ended up quitting CS when version 1.6 was released. We hated the changes so much and came to the realization that we were never going to make it to the CPL. We both went our separate ways freshman year of college. He attended Salem State College while I went to UMass Amherst."

"Though this didn't keep us apart. Sean would often drive out to Amherst for the weekend to party with me. Boy that kid could drink!"

That split didn't last for long, as the world's most popular MMORPG of all time was about to be released: Blizzard's World of WarCraft.

"After the first semester was over, I recall Sean coming over to my parents house and bringing his laptop, he tried convincing me to get this game called World of Warcraft back in December of 2004", says Kelly. "I hadn't much interest in MMORPG's, but due to his convincing nature and ton of peer pressure, I decided that I would."

"It was shortly after Christmas, December 29th, and we started off to a GameStop. We embarked on a journey to the closest GameStop probably around 6pm EST and no luck, they were sold out. We drove a couple towns over to the next GameStop only to run into the same result. Well, we figured what the hell, we drove to the next closest GameStop while I was calling 411 (before Smartphones) for phone numbers to all of the GameStops in the area. Sean really wanted me to get this game but we were having shit for luck. Finally I got ahold of a GameStop in Portsmouth, NH area that had ONE copy of WoW left. Sean sped there as fast as he could to get there just before it closed at 10pm. We finally had our copy of World of WarCraft."

Collier began his police career around this time by interning at the Somerville Police Department in 2004 in the IT department, before later becoming a Somerville Auxiliary Officer.

"He was roughly level 22 and I was just starting out. I had a lot of work to do to catch him. He gave me advice and we sat next to each other for the remainder of the school break, leveling my character to catch him. Within a week and a half I caught up to him. With Sean being an intern at a Police Station, he didn't have much time and I started pulling away. As I hit level 30 and he was still back at 27, he got pissed and stopped playing WoW, as he really didn't have the time, either.

"I ended up being consumed by the game, craving the end-game content. I started 40-man raids with an Alliance team on Skullcrusher and made some Horde friends and re-rolled Horde on Skullcrusher. I got Sean to level 60 and joined Nightmares Asylum (for a while they were thought to have world first on Ragnaros) which was a guild that had pretty much every server first and came close a couple of time for World First."

"Throughout casually playing WoW and the end of his CS days, Sean had also began toying with Battlefield 1942 and played that in his spare time. He continued playing Battlefield throughout all of college and up until present day. He switched over to Xbox in 2008 because all of his new friends had been console gamers."

"Even until recently, Sean and his roommate Travis 'Vaporburn' Dixon would setup their flatscreens next to each other in the living room and game for hours while throwing back a few brews. He also started getting back into Starcraft II after the release of Heart of the Swarm."

"Sean had a natural talent for any video games and would instantly develop skills that were superior to above average gamers with absolutely no effort at all. This was how he was with computers, HTML and graphic design. Even though I knew he had wanted to become a Police Officer all of his life, I really thought he was going to pursue web design or graphic design."

Collier was posthumously sworn-in to his dream job at the Somerville police department in August of last year. Collier and Kelly had been playing and watching video games since they were kids. Before esports had a name, let alone an industry. Two gamers whom we can look at and see a lot of ourselves in. Kelly will always see himself in Collier.

"Sean was a lively and curious individual who wanted to get to know about and explore everything that there was to be explored. He never turned down a good adventure and was always up for a beer. He would do anything for anyone and always was helping people when he could. His dark sense of humor as well was a riot and definitely could make people laugh. It's funny because he truly couldn't stand crowds or large groups of people and at first wouldn't mesh well. Once he had a few bevvies to loosen up, he was the life of the party with a good balance of crazy antics and laughter."

"I deeply regret not being able to spend more time with him as we both had been pursuing demanding careers. After I lost my leg, we promised to spend more time hanging out and he was going to help me rehab this summer by hiking together, get me rock climbing but most of all be around him. Sean I will forever miss you and there will always be a part of my heart with emptiness that can never be filled. Sean and I were brothers, I loved him.

"Not only will Sean be my early influence into competitve gaming, he will always be a major influence on who I am and continue to grow to be. Sean loved to do many things and went through many phases in life. But no matter where he went or what he did in life, he always kept gaming close to his heart. This is the essence of a true gamer. Love you brother."

Today at a memorial for the passing of Sean Collier, US senators Edward Markey and Elizabeth Warren praised Collier, and Cambridge Mayor David P. Maher said the intersection at Main and Vassar where he was killed would now be called Sean Collier Square in his honor.

Collier was 26-years old.