Wendy Budde (Angela's Sister)

Police would learn both Christy and Hilda showed signs of sexual assault, but they feared they would face challenges making the case.

How difficult is it to prove a crime took place when the victims were recreationally using drugs?

This makes the case extremely hard.

I told Jan early on that this was going to be a near impossible case to prove.

Yeah, at first, it's a whodunit.

It just became what actually happened.

And that's what was the difficulty of this case.

Detective Jonathan Vander Lee says the pressure was on to locate any evidence of what happened after Christy and Hilda met David Pierce that night.

You got to get this evidence before it disappears.

Police did have some luck, starting with this footage from outside that warehouse party, which they say shows the women leaving with Pierce, Osborne, and a friend of theirs, 47-year-old Michael Ansbach, on their way to Pierce's apartment.

Police also uncovered this text exchange from moments earlier when the women were still inside that party.

Do you want Coke, asks Hilda.

Yes, replies Christy.

Hilda texted back, I'm in the kitchen, let's do a line.

Witnesses say Pierce supplied that cocaine, which Jan says was not a common choice for Christy.

Police determined the group arrived at Pierce's apartment a little after 5 a.m.

The women aren't seen again until 11 hours later when, at 4.30 in the afternoon, a security camera recorded this grainy image showing Pierce with Christie over his shoulder at the top of the stairs.

Police say Osbourne is carrying her bag.

35 minutes later, at the hospital, Pierce, wearing a black sweatshirt, helps take Christy's body out of the car.

Osborne looks on.