Leroy Jethro Gardener was born into a muggle family in Salem, Massachusetts on September 2, 1951. The Gardeners were a hardworking family. Jackson ran a small gas station in a suburb of Salem. Jethro's mother died when he was young. Jethro was 9 when she died of cancer after a long convalescence. When she died, Jethro became angry at his father's attempt to comfort him, translating the care into smothering affection. He felt the need to get out, so he would spend all his time out in the garage tinkering with the cars there. He learned shortly after his mother's death that he had something more than the other kids. It wasn't a surprise to him, then, when wizards with dark glasses and suits showed up at his doorstep.
He entered Bear Claw at the school there in Salem, hitting high averages in most everything. He excelled in Defense Against the Dark Arts and Charms. He was driven to do whatever he could to get away from home. He still went home on breaks, but rarely spoke to his father, continuing his habit of spending time in the garage. Shortly after graduating from Salem, Jethro enlisted in the Magical branch of the US Marine Corps, learning easily how to fight both in the muggle and magical ways. He became a sniper, excelling in both wandsight and long-range rifle shots. He served overseas in heavy combat areas, seeing firsthand what both muggle and magical people would do to each other. This instilled in him the deep need to protect those he loves.
About halfway through his tour, he was training in an undisclosed location, and was shot in the knee. The doctors decided since it was a purely muggle wound, they'd let it heal in a mostly muggle manner. (These particular doctors / healers were dressed down severely for doing that way, but the damage had been done.) He spent time back at home while recuperating, angry at the Healers for not fixing him up properly, at the idiot who shot him, and at life in general. The only highlight in these dark days was meeting the love of his life. Shannon lived only a few streets down from him, and she worked at a local magical items shop, helping her cousin out with small things like inventory. They began talking, and Shannon gave him a list of rules that she lived by. Jethro adopted the practice. He married her between tours, spending a couple glorious months just staying home with his beautiful redheaded wife. He returned to 'war' more eager to protect than to kill. His superiors noticed and placed him in a training role training younger Marines. It also kept him at home at night, which was perfectly alright with him. A few years later, he became the proud father of Kelly Allison Gardener. Jethro was a devoted, doting father, bringing home trinkets and toys for his baby girl on a regular basis. Life proceeded apace, and the Gardener family was happy.
However, when Kelly was six, duty called again, and Jethro left to go serve overseas. Kelly begged him not to go, but he was adamant. His old unit had found a cache of potions that were volatile and his team was trying to track down the supplier. It took them the better part of two years, but they did it. When they were raiding the supplier's warehouse, someone zigged when they should have zagged. They dropped a crate of the potion, setting off a chain reaction that blew the whole warehouse sky-high. He survived, but was sent home with injuries that would keep him out of the service for months. While he recovered, he heard the most devastating news. Shannon and Kelly had been killed. They'd been shot by a drug dealer who had wanted Shannon not to testify against him. Kelly was eight. When he left the hospital, he sat beside his bed, playing with his wand, considering turning it against himself. It was a very near thing, but a friend of his stopped him, and suggested he do something about the kind of thing that had caused her death.
He joined the MBI (Magical Bureau of Investigation), got the information on her killer and dispatched him handily. He worked as an Agent for the MBI for several years, marrying three different women in turn who reminded him of Shannon in some way. Maria had her fire, which turned into hatred when he wouldn't give in to some demands she made. Stephanie had her charm, which seduced men into her bed easily, even after she was married to him. Diane had her drive, which drained his bank accounts of gold, and then married his best friend Thomas Fogerty.
After Diane left him and he got the divorce papers squared away, Jethro decided he'd had enough, and asked for a special assignment. He was assigned to the United Kingdom as an Auror intent on helping the fight against their so-called 'Dark Lord' and making sure that his terrorism doesn't cross the sea to his homeland.
Personality
Jethro is a solid rock. He's silent, unyielding, and supportive. He was a fairly stereotypical Bear Claw, and an excellent Marine. He doesn't speak much, but when he does, it's intelligent, or provoking. He excels at catching Dark Wizards because he just waits them out, or startles them into giving information. He also has a disregard for protocol that does not fit his own personal set of rules.
1 Never let suspects stay together. (or) Never screw (over) your partner.
2 Always wear gloves at a crime scene.
3 Don't believe what you're told. Double check. (or) Never be unreachable.
4 If you have a secret, the best thing is to keep it to yourself. The second-best is to tell one other person if you must. There is no third best.
5 You don't waste good.
6 Never say you're sorry. It's a sign of weakness.
7 Always be specific when you lie.
8 Never take anything for granted.
9 Never go anywhere without a knife.
10 Never get personally involved in a case.
11 When the job is done, walk away.
12 Never date a coworker.
13 Never, ever involve lawyers.
15 Always work as a team.
16 If someone thinks they have the upper hand, break it.
18 It's better to ask forgiveness than ask permission.
22 Never, ever interrupt me in interrogation.
23 Never mess with a Marine's coffee if you want to live.
27 There are two ways to follow someone. 1st way - they never notice you; 2nd way - they only notice you.
35 Always watch the watchers.
36 If it feels like you're being played, you probably are.
38 Your case, your lead.
39 There is no such thing as coincidence.
40 If it seems like someone's out to get you, they are.
42 Don't ever accept an apology from someone that just sucker-punched you
44 First things first, hide the women and children
45 Clean up your messes.
51 Sometimes - you're wrong
69 Never trust a woman who doesn't trust her man.
Jethro and Jane Shepard had an on-again, off-again affair throughout several years and several operations in Eastern Europe. Jethro was still mourning his first wife, and Jane was aware of it, and not looking for more than occasional fun and comfort. It's made things tricky for them, and part of the reason why Jethro created Rule 12.
Jethro helped train Lt. Commander Jake Morgan and found him to be a decent guy (for a sailor). When he came back into Jethro's life, he became a source of pride and worry.
Jethro also helped train Siobhan Noble. He's trained her in hand-to-hand techniques, and basic physical fitness. He's not sure what's going on specifically between her, Morgan and Snape, but something is fishy.
Jethro builds boats the old-fashioned way, with no power tools or magic. He uses it as stress relief, then shrinks the boats and gives them away as toys to hospitals like St. Mungo's for their Children's Wards. He can also make other toys, and does, but he prefers the work on the larger projects.
Siobhan: "Oh, well. Means I get more of a break between runnin' for my life and your new hobby."
Jethro: "Knockin' you on your ass' good for ya, Noble. Won't be long you'll be doin' the same t' me." — Jethro's New Hobby
Jethro: "Use your wand, not your purse, Morgan." — Gear Up!
Trivia and Notes:
Jethro has the highest solve rate in his division of the MBI. However, he's kind of known as a Lone Wolf.
He's gruff and tough, but around children, he's a papa bear. He'll do whatever it takes to protect them.
He's a chauvinist, and proud of it. He doesn't think women are useless, but he does feel the need to protect them, as though he were a chivalrous knight or something.