Fantasy novel involving a mall security officer who prevents a man from blowing up the mall with a dead man's switch

Question

You would think that a fantasy novel with a main character who is a mall security guard would be easier for me to find. Due to another question I answered recently, I wound up on the TV Tropes page for Dead Man's Switch, and it made me suddenly remember a paperback novel I read in the mid 1990s in Ashland, KY. The plot of the novel had a night watchman at a mall somehow getting involved with the supernatural. What's making things difficult is that the details that are sticking in my mind are the non-supernatural ones. What I do remember:

1. The main character had had a promising sports career (or at least believed he did) until he jumped in on a scene where a guy was getting beat up by several other guys, trying to be a hero. It turns out that the guy being beat up had done the crime he was accused of (I want to say some sort of sexual assault on someone's sister) and in the course of the fight, the protagonist suffered a game-ending injury. I have a vague idea that it had to do with a joint getting damage like a knee or a shoulder.
2. Somewhere in the narrative, the protagonist sees a disheveled guy in a trenchcoat and gets a really bad feeling about the situation. He winds up acting on it and notices that the guy is holding a bicycle brake squeezed in one hand. Working on instinct, he holds that hand shut during the ensuing fight, getting someone to wrap several layers of packing tape around it after he's taken the suspect down to ensure that he doesn't let go. It turns out that the person he took down had a suicide bomb under his coat, linked to the switch. I want to say that the suicide bomber had some sort of religious motivation for doing this, some sort of "cleanse the unbelievers".
3. Maddeningly enough, I'm vague on the actual fantasy aspect. I want to say that it involves elves, with the mall having been built over some sort of magic source. I know that sounds like a Mercedes Lackey plot, but I haven't found a match, although malls and elves were apparently the genesis of the "Elves in L.A." series she did with Rosemary Edgehill.
4. I think at some point, the security guard had been running late on his rounds due to his involvement with the elves and whatnot, and he was rushing through the rest of the night's checkpoints, which was noticed by a superior who tried to use it against him (and who assumed it had something to do with drugs or petty theft).

Answer 1

Mall Purchase Night by Rick Cook.

When Andy Westin became a security guard at Black Oak Mall he had no idea what he was getting into. This particular mall is built on an elven power source—the actual gateway between Elfland and Earth. This has made it a place of conflict between some very heavy elven hitters. The good guys are merely ruthless. The bad guys are evil incarnate. On the eve before May Day, the conflict threatens to boil over. And all that stands between thousands of shoppers and the worst Faery has to offer is one bemused security guard. That is, if the elven princess doesn’t get him first!

The bomber is a character known as The Preacher:

The Preacher took his time, working carefully and stopping often to check his work. Batteries from the flashlight under the drivers seat, copper wire left over from a long-ago house wiring job, a purple gym bag tucked away in a corner that he could barely stand to look at, the things nestled in foam in the specially constructed metal box in the glove compartment and finally the brake lever off a child’s bicycle. The Preacher's hand shook and his eyes filled with tears as he remembered his casual promise to take it by the shop and fix it as good as new – and how the promise became moot before he could ever keep it. But the Lord was with him and the Lord made him strong.

You've misremembered the scene slightly. Andy is suspicious because the man looks too relaxed:

"Uh-huh," Andy mumbled. It wasn’t that the old man was tense, he realized, it was exactly the opposite. He seemed utterly relaxed, as if he was completely at peace with himself. With a chill Andy realized where he had seen that kind of calm before. Someone who’d been under a lot of stress and had made a decision that simplified their lives. Some criminals were like that after they confessed. So were some jumpers – the ones you couldn’t stop.