Police aren't releasing many details about the mysterious murder of 18-year old trans teen Angie Zapata, but they're definitely digging into her background:

The beating death of a transgender teenager in Colorado may have been provoked by her lifestyle, police said.

"The bottom line is, we can't rule it in, we can't rule it out," Sgt. Joseph Tymkowych, a police spokesman in Greeley, Colo., told ABCNews.com.

Born a male, Justin Zapata, 18, identified herself as a woman and was known to family and friends as Angie. Her body was found in her apartment a week ago, with wounds to the head and face, police say. Missing was her green 2003 Chrysler PT Cruiser. Authorities have not
yet recovered the car, which they hope will provide evidence that might help crack the case.

"The sooner we can find it, the better," Tymkowych said of the car.
…
[Police] think the suspect — or suspects — likely had some type of relationship with Zapata.

"We believe the victim knew or was an acquaintance with the suspect," Tymkowych said, adding that they have almost been able to clear a former roommate initially identified as a possible person of interest.

Tymkowych also mentioned that since Zapata didn't legally change her name, prosecutors must refer to her as Justin Zapata, "We don't have a problem using 'Angie.' We don't want to offend the family or anyone with gender concerns, but for it to be a good, clean prosecution, we can't identify a victim who doesn't exist."