I'm not sure if anyone still reads this thread but I just read through all this and had an idea that I haven't seen brought up yet.
Sgt. D had said that she had contact with LE in 1995 and that she was not arrested or detained. He also said the record of this contact was difficult to find.
If Sgt D had run any sort of search for her name, it would not have been difficult to find. I do not think the record was in her name, but it may have very well been a criminal record or incident report under the name of someone she was with.
I would start by looking for criminal records in the Hurst area for the names of people she knew. My guess is that it was hard to find because he ran the criminal records of the names Deannas family gave him and then had to read through the reports in other jurisdictions to eventually find a mention of her.
Criminal records are public so if any of her known friends/associates were 18 or over in 1995 and had a criminal incident in Hurst, you may find the reference to her in the police report or court documents b