The killer had claimed she'd acted as a result of schizophrenic voices in her head, murdering her entire family while they sat around the Christmas tree before later managing to grab a detective's gun outside of the interrogation room and shooting herself in the head.
As much as Bobby wanted to pretend the case hadn't haunted him, it had left him wondering if one day that was what he'd become. It was times like these that he wanted to be alone with his thoughts. It wouldn't be fair to burden anybody with his concerns, but especially not his partner and especially not at Christmas time and especially when she had revealed days earlier how excited she was to see her nephew for Christmas dinner that night. Instead, he gathered his things up preparing to leave while she was outside taking a phone call from her sister.
However, Alex came back into the room before he had the chance to do so.
"Have fun at your sister's." He mumbled hoping it would cause her to leave before she had the chance to realize he planned to spend his Christmas Eve downing most of a bottle of wine and marinating in his own inner demons.
"Liz cancelled. Nathan caught the flu from one of school mates." Alex offered in response. "I'm going to have to settle for Christmas Eve takeout." After a pause she suggested "Come home with me, I don't think my waistline would appreciate it if I ate all the cookies ,I was going to bring Nathan to leave out for Santa, all by myself."