A Texas woman charged with stabbing her boyfriend in the back with a steak knife pleaded not guilty and not guilty by reason of mental illness Wednesday in Natrona County District Court.

A judge ordered a mental evaluation for Deanna Collette McCreery, 38. Legal proceedings against her will be put on hold pending the outcome of that evaluation, which could take several weeks.

During her initial court appearance last month, McCreery described herself as bipolar with schizophrenic tendencies.

Natrona County sheriff's deputies arrested McCreery on July 6 in connection with the stabbing of her boyfriend, Raymond Porterfield, at a Casper Mountain campground. After the stabbing, she drove him to the hospital, where he was treated for a punctured lung, authorities say.

Witnesses told sheriff's investigators McCreery became upset before the stabbing because Porterfield woke her up for a meal.

At first, Porterfield claimed a man named "Johnny," whom he'd met earlier that day, had stabbed him, an investigator testified at McCreery's preliminary hearing last month. However, Porterfield couldn't explain why Johnny had stabbed him.

Under further questioning, he told investigators he didn't want to get McCreery in trouble, but that she had stabbed him.

McCreery and Porterfield arrived in Casper two days before the stabbing for work, and were camping on the mountain, she told a judge in July.

On the day of the stabbing, McCreery and Porterfield apparently met another couple at a grocery store and they all decided to have a picnic on the mountain. They drank vodka and cooked bratwurst and burgers.

McCreery fell asleep, and when her boyfriend woke her up to tell her the meal was ready, she got upset and started honking a truck's horn before stabbing him, according to an investigator's testimony at the preliminary hearing.

McCreery is charged with aggravated assault and faces up to 10 years in prison if convicted.

Reach crime reporter Joshua Wolfson at (307) 266-0582 or at josh.wolfson@trib.com.