Woman Cut Off Boyfriend’s Manhood Then Gave Him Ibuprofen Before His Death

A Colorado woman accused of stabbing her boyfriend and cutting off his genitals before allegedly giving him ibuprofen for the pain has entered a plea of not guilty by reason of insanity.

Shenting Guo is facing a second-degree murder charge in the May 2024 death of her boyfriend, 38-year-old Dustin Nalls, following what authorities say was a horrifying argument inside their home.

Guo, 34, is also accused of causing bodily injury, recklessly causing another person’s death and knowingly abusing a corpse.

The disturbing case can move forward only after Guo undergoes another psychiatric evaluation.

She has previously been found incompetent to stand trial but potentially restorable, and court records indicate she is on the schizophrenia spectrum.

If doctors determine she remains unable to understand the proceedings or assist in her own defense, she could be committed to a Colorado Department of Human Services mental health facility until she is considered competent.

Authorities say the deadly confrontation began after Guo mistakenly believed she was pregnant and the couple began arguing over whether Nalls would have been the father.

According to an arrest affidavit, Guo told investigators she wanted to go to sleep but claimed Nalls would not allow her to.

She allegedly warned him: “If you don’t let me sleep, I’m going to stab you.”

Police say she then stabbed Nalls in the leg before going to bed.

But the violence allegedly did not end there.

Investigators said Guo later became suspicious that Nalls was pretending to be asleep. She allegedly cut off his genitals and threw them into a bathroom trash can.

Authorities say Guo told investigators Nalls did not appear to be showing much pain at the time.

She then allegedly left the home and went to a nearby City Market, where she purchased rubbing alcohol, ibuprofen and beer.

According to the affidavit, she did not buy bandages.

Guo allegedly returned and tried to treat Nalls’ injuries, giving him ibuprofen for the pain. She later told police that he appeared to lose consciousness after the stabbing.

By the time emergency crews arrived, Nalls was dead.

Guo allegedly told investigators she never intended to kill her boyfriend but admitted stabbing him because she was “so angry.”

Her insanity plea now puts her mental condition at the center of the case, with a psychiatric evaluation expected to determine whether she can proceed to trial.

The charges against Guo remain allegations, and she has not been convicted.