Personal disclaimer: I am a sex positive person with no issues with fetish communities. I also defend art and music like no other... in this context though, no beuno.
The following details are from Brendt Christensens Fetlife profile, username Akuma689. I believe this gives much insight into his interests and possible motive for the kidnapping and probable murder of Yingying. Of particular interest is the themed groups (abduction, ropes/chains bondage, fear, domination, BDSM, etc) he was a member of. I did not enter the vast majority of these groups. I also did not find any posts made by BC, but it's possible that the search function doesn't allow to search by user or that he was a lurker. I did see some social interaction between he and other members local to him, I've redacted that content from my screen shots for their privacy.
I viewed this site in the wee hours (PST) of July 1st, so keep that in mind when reading 24 days ago and other time references. Given that I don't know what time zone Fetlife is in, the dates could be +/- 1 day as I was there between midnight and 1 am.
You can see the shots here:
https://drive.google.com/folderview?id=0BxaBCXtm5qnCNWJUbENlc1NRMDQ
I think that BC was on this site to network with folks with similar interests, though I bet he's among the very few that took his fantasy to a real life level. I have to wonder used the fantasy groups to inspire his crimes or if any of this content can provide insight into what he did to Yingying. Could he have filmed any part of the crime? Was she bound?
June 9: Yingying disappears
June 7: Date of last activity on Fetlife
Info on Fetlife:*
Akuma689, 28M Champaign, Ill
Married, dating
Is looking for a relationship, and mentor/teacher, and play partner, princess by day, s**t by night, friendship, and mistress, a sub, a slave.
24 days prior to July 1st, approximately June 7, two days before Yingying disappears. BC updates his profile and engages in social activity that I won't detail out of respect for the other parties privacy.
2 months prior to July 1: Active on Fetlife
****** Updates profile several times
**** Changes role to Dominant
***** Changes his role to Hedonist
****** Lists himself as married
****** Lists himself as being interested in (this list is snipped for focus)
Watching others wear shackles
Sex with strangers
Giving sensual domination
Sensory deprivation
Everything to do with sadomasochism
Rituals
Outdoor sex
Giving Objectification
Making home movies
Giving fear
Face slapping
Exhibitionism
Emotional sadism
Degradation
Defilement
Watching others wear chains
Giving belt whippings
Giving behavior modification
Receiving begging
Giving bare bottom spanking
Everything to do with: Anonymous encounters
Everything to do with Abduction play
Everything to do with Consensual nonconsent play
Giving Domination
Giving humiliation
Giving Pain
Giving sadism
Giving discipline
Giving Master/slave
Giving Mind *advertiser censored**ks
Everything to do with Predator/Prey
Giving bondage
Also two months prior to July 1st, joined groups (snipped)
5 different local BDSM groups
Domestic discipline
Fear play
Submissive/slaves
Mental BDSM, verbal humiliation, & mind fs
Practicing polyamory
Primal, all types
Male owner, female property
Consensual nonconsent, blackmail, and slavery
Rope bondage
Predicament bondage
Behavior modification
Anonymous encounters
Abduction 101
Three months prior to July 1st
·******** Joined Fetlife
·******** Changed nickname from Buck_Dich689 to Akuma689
(Buck Dich is a song with very strong lyrics describing abuse and degradation
http://www.lyricsfreak.com/r/rammstein/bck+dich+bend+down+english_20619555.html)
Eta: why I'm so sure it's him:
He uses the prefix Akuma in other SM handles (Steam for example), 689 refers to his month and year of birth and is also used in other SM (Okcupid). The age, sex, and specific location are correct. There were pics including him in friends' profiles, I did not screen shot those as they were not him his profile.
Fetlife management has apparently confirmed his identity as well, there was a thread in Abduction 101 that bore his full real name shortly before the group disappeared from view. I didnt get to read it before it poofed. Not sure if the group has been deleted or is in some sort of invisible mode or something, I didn't officially join the group, I just lurked around. All his friends have removed references to relationships with him.
I'm a skeptic by nature, but given all this...I'm 100% confident this is BC.