It's no surprise to anyone that many media outlets do their best to sensationalize crime. In this case, it's not only been sensationalized but
romanticized from the start due to the possible Runaway Bride scenario. One of the first articles I read once Annie's body was found was in the
New Haven Independent, which stated LE had a suspect and it was a case of "unrequited love". The article has since been updated, with the remark that LE has ruled this out as a motive:
http://newhavenindependent.org/archives/2009/09/serious_suspect.php
IMO the newer motive of workplace violence may be an attempt to stem prurient interest in the case -- sex sells, after all. No doubt Yale doesn't like this kind of attention. But if no evidence ends up being found to support a sexual motive, then it must be that RC was the proverbial ticking time bomb employee and Annie was his unfortunate victim.
Still, I think it's beyond noteworthy that RC's only other known involvement in violent behavior is when his HS gf broke up with him.
It could be that since Annie's fiance was out of town (albeit only a couple of hours drive-time away, at most) and she and her fiance were ambitious scientists who may have put career first in many ways (i.e., not spending as much time together as some other couples do), it was easier for RC -- as a young man who's only lived and worked near where he was born, who worked with his gf and other family members, etc. -- to misinterpret or fail to appreciate the personal dynamics of a couple like Annie and her fiance. Their relative distance could've fueled his imagination and hope for something beyond a professional relationship with Annie. If so, I can imagine him being emotionally gutted on the fateful day especially if it was his last contact with her before her marriage, when confronted with the undeniable reality of her committment to someone else.
So, even though I admittedly may be influenced by media who still try to infer a sexual motive (whether overtly or just by illustrating their dryer stories with photos of Annie in cleavage-baring camisoles), I'm still inclined to believe the "unrequited love" motive, regardless of what Yale or the NHPD say.