You're Lucifer Morningstar's sister who left heaven to keep an eye on him after he and Maze left hell to party in LA. While working Delilah's murder with Detective Decker, they realize someone has been following them. After you let the detective "surprise" you and cuff you, she walked you back to Lucifer and when she pulled your hood back…
"Y/N?" Lucifer was taken aback when he realized that he knew his stalker.
"You know her?" the detective asked as she tightened the cuffs on your wrists.
"Yes, quite well in fact," Lucifer said, as he tried to process the fact that you were actually standing in front of him. Chloe was surprised by how you seemed to affect Lucifer, "She's my sister. Tell me, how long have you been in LA?"
"Just as long as you have been, brother," you smirked, "you must be going soft on me, unable to sniff out the angel on your tail."
"So, you've been following me?" Lucifer crossed his arms and raised his eyebrows.
"More like keeping tabs," you shrugged.
"So, wait," Chloe interrupted, "You're actually his sister?"
"Oh, yes," you grinned mischievously, "and I'm his favorite too. I'm the only one of our siblings who bothered to visit him in hell."
"So, you're in on his little delusion, too?" Chloe groaned.
"I promise that it's anything but a delusion, Detective Decker," You replied seriously.
"How did you-"
"Know your name?" you finished the detective's thought for her, "Every cop in LA knows who you are, thanks to the Palmetto Street thing."
"So you're a cop?" Lucifer asked, "well isn't that just the perfect job for daddy's little soldier."
"Don't cop an attitude with me, Lucifer" you warned, "I left heaven to keep an eye on you against father's wishes."
"You little rebel you," Lucifer grinned, "why have you kept your distance then?"
"I wanted to keep my distance after... well, you know," you averted your eyes, uncomfortable with the subject.
"Ah yes, well, that is all water under the bridge now," Lucifer waved off your concerns.
"What unit are you with?" Chloe pushed the conversation back to being about the mystery woman.
"Vice," The woman replied, "I'm sorry I've ignored my manners. My name is Detective (Y/N) (Y/L/N), but you can call me (Y/N/N)."
"I've heard of you," Chloe said, "you're a bit of a rising star. Made detective in like 3 years and took down that smuggling ring a few months ago."
"The Devil's Triad case isn't really much to brag about," you said modestly, "I really just didn't like them mocking my brother."
"Right, because he's the devil," Chloe said sarcastically.
"Exactly," you smiled, "Now that we've made introductions, would you mind taking the cuffs off?"
"Right," Chloe said as she unlocked the cuffs and then put them back on her belt, "Sorry about that."
"No worries, I don't mind a little bondage," you winked, eliciting a look of disgust from Chloe, "Besides, I was the one sneaking around like a criminal. So, what would you say to an extra set of hands on your-?"
"I don't think the detective is into girls," Lucifer cut you off so that he could make your question sexual.
"Hush, Lu," you chastised him and made sure to use your favorite nickname for him because you know how much he hates it, "What I was trying to ask is if you would like some help with this case."
"Oh, I really don't think that's necessary," Chloe shook her head, "I think we've got it under control."
"Don't be ridiculous, Detective," Lucifer said, "We could use all-hands-on-deck for this one and there are none more capable than (Y/N). She was our father's favorite bloodhound."
"I wasn't a bloodhound, Lucifer," you said crossly, "I was-"
"A bounty hunter?" Lucifer offered, "One of the many hats you wore was chasing down errant souls and celestial beings."
"He's exaggerating," you told Chloe, "but you're aware of my reputation in the department, so I'll let that speak for me, and not my wayward brother."
"Alright, fine," Chloe relented.
"Splendid," you grinned and clapped your hands together, "Let's get to work, shall we?"