NOTE: This is all my interpretation of the character. I take liberties here and there and have my own, more thought-out backstory for Ichabod. Please respect that.
Ichabod Crane was born to a loving mother and a withdrawn father. His father was a priest, and so he spent very little time with him as a child, most of the time only doing so to make him study to be like him. His mother was hiding a secret, however. She had a gift of magic, and her young son had witnessed it on multiple occasions. Eventually, his father found out and went into a fit of rage, disgusted by what his wife was. He took her into a room filled with torture devices and locked her into an iron maiden. As he left young Ichabod, who had been hiding outside, darted in before his father noticed. This is where he found his mother, and in shock, he jumped back, his hands falling onto spikes, scarring them forever. After his mother's death, his father became very abusive towards him, now having nothing to hold him back from mistreating his son. At age fifteen, Ichabod ran away, eventually making it to New York, where he became a constable, despite his aversion towards blood. He was eventually assigned to the Sleepy Hollow case.
Once arriving at Sleepy Hollow, he originally scoffed at the town's people, who believed a headless hessian was the killer. However, after encountering the hessian himself, he became set on finding out who was responsible for summoning the hessian back from hell to kill for them. He eventually discovered it was the step-mother of Katrina VanTassel, a young woman who was helping him. She was angry at the VanTassel family for taking their cottage. Her family lived in a cottage in the woods but were then kicked out and the VanTassel's moved in. After moving out, she came up with the idea to summon the hessian. She married into the family to gain their trust before killing off people who had figured out or might figure out her identity. Ichabod was able to stop her with the help of Katrina and the orphaned son of one of the victims. They succeed, and the hessian returned to hell with his summoner. After the events of the murders, Ichabod returns to New York with Katrina and the orphaned child, whom he adopted.
Katrina and Ichabod are in a relationship briefly before splitting due to conflicting opinions, Katrina not liking him working so much, and Ichabod simply not quite feeling the same way she felt. Katrina returned to Sleepy Hollow, while Ichabod and Jon Masbath (the orphaned child from before) stayed in New York. A few years later while working on a case he meets Eve, whom he falls for quickly. The two end up together and she returns to the city with him. They remain a couple, and Ichabod even somehow convinces his superiors to let her work with him. They are hopelessly in love with each other.
The moon was in full bloom that night as the dead rose from their eternal slumbers to roam the Earth once more. These lost souls would spend the next eight hours causing all kinds of mayhem to the locals. Whether it be the most sinister of crimes, or just watching a loved one close their eyes for the night, it was pure chaos during the late evening hours. Emily was indeed a lost soul, but not at all by choice.
Rising from her eternal slumber, Emily took in the crisp summer air. A faint smile appeared across her face as she took her first steps of the evening. In the far-off distance, she could hear the blood-curdling screams from the demons of the underworld terrorizing the locals. Just a few miles north of her, the sounds of soft wails from those who were trapped between life and death and doomed to relive each of their days on constant repeat. It was the symphony of the night, and it was a song that Emily was truly getting sick of hearing.
Emerging from the shadow of the grand oak tree in front of her, Emily felt her body transform. Unlike most ghostly figures one would see, Emily would not remain in her decayed form when in the presence of a human. Instead, she would regain her original features that she had before her demise, essentially becoming a walking corpse, just not the flesh-eating kind. Her once tattered dress regained its seams, and her bony fingers were now porcelain. "You seem lost in the wind, my good sir. Perhaps I could be of some assistance?"