Hot Scientist: Calleigh is a blonde, leggy Southern girl who likes guns, Natalia is a tall, curvy latina, Eric is half-Cuban/half-Russian, Ryan has perfectly tousled hair and Maxine Valera is fairly cute. Also, yes, some people do find David Caruso sexy.
Jumping Off the Slippery Slope: Seems to be going this way after his near-death experience. He is noticeably more vicious and ruthless, savagely beating a suspect and even letting a man fall to his death as he begged for Horatio to help him. Granted, one man had killed a police officer and was involved in a kidnapping, and the other man was a pedophile with a long history of abducting and molesting young female beauty pageant contestants, but still.
Pedophile: *While hanging onto a ledge* I can change - I know it! Horatio: I doubt that. Pedophile: *His fingers starting to slip* You have to help me! Horatio: *Coldly and dispassionately, while stepping away from the man* Do I? Pedophile: *Falls to his death*
Jerkass: Definitely had his moments, usually when speaking to women. He told one victim of harassment that it was her fault and she'd lead the guy on (she hadn't), and was rude to other female characters (excepting Alexx, Megan, Calleigh and Yelena).
Killed Off for Real: Speed is shot and killed halfway through the Season 3 premiere by security guards at a jewelry store when his gun jams thanks to negligent keeping.
Tempting Fate: When walking into a jewelry store with Horatio, Speed discusses expensive cars, disdaining them in favor of his bike. Caine mentions that he might need "something with doors" some day. Speed says he has plenty of time. He is fatally shot not five minutes later.
The Mole: Was working for Internal Affairs during his relationship with Calleigh.
Jerk with a Heart of Gold: Occasionally. He's usually called on it, though. Even so, he's proven to be a very capable cop, and extremely compassionate when he needs to be.
What Happened to the Mouse?: Her final appearance was in the Season 7 finale, when she assists Horatio with an escaped and dying fugitive; although she was advertised as being billed for more guest appearances, her character and her son's character were dropped with no announcement instead, invoking Chuck Cunningham Syndrome.
Put on a Bus: Alexx leaves the morgue in Season 6 to become an ER doctor. She's occasionally appeared since then, usually when one of the team have been injured in the line of duty. She returned for a few appearances past that.