U.S. Army Pfc. Dewayne Johnson sits with his teammates during an exercise at Helemano Military Reservation, Hawaii, in November 2023. (Joshua Linfoot/U.S. Army)

WHEELER ARMY AIRFIELD, Hawaii — Army Pfc. Dewayne Arthur Johnson II pleaded guilty Tuesday to the rage-fueled killing of his wife and her unborn child with a machete last summer.

In a plea deal accepted by Judge Rebecca Farrell in the Wheeler Army Airfield courthouse, Johnson, 29, pleaded guilty to two counts of voluntary manslaughter, thus avoiding a trial for the murder charges referred by the Army Office of Special Trial Counsel in February.

Voluntary manslaughter lacks the premeditation aspect of murder, and it is typically committed in the “heat of passion due to fear or rage,” Farrell said.

In a calm, emotionless voice, Johnson described under oath how he had killed Mischa Johnson, 19, with a single blow to the head with a machete, dismembered her body, bagged it and disposed of it in a dumpster bound for an incinerator.

Her body has not been found.

Mischa Mabeline Kaalohilani Johnson was last seen in her home at Schofield Barracks, Hawaii, in July 2024. (Honolulu Police Department)

Farrell will begin the sentencing phase of the court-martial on Wednesday. Johnson faces a sentence of between 18 to 23 years based on the plea agreement.

He also pleaded guilty to obstruction of justice and providing false official statements.

A charge for possession of child pornography and the production and distribution of child pornography was dropped under the plea deal.

Johnson reported his wife missing on Aug. 1, setting off a flurry of searches on and around Schofield Barracks, where the couple lived. In fact, Johnson had killed her more than two weeks earlier on July 12, he said in court.

The couple frequently quarreled over the soldier’s interest in other women, he said.

On July 12, Mischa Johnson objected to his choice of movie to watch at home because the lead actress resembled a woman with whom she believed he was sexually involved, he said.

They argued in several rooms of their home and ended up in the upstairs bedroom, Johnson said.

“I picked up the machete next to the bed,” he said. “I’d never hit her before, so I think she thought I wouldn’t do anything.

“This day she said something she never said before: This child will never know you even existed,” he said.

“I was overwhelmed with rage at the thought of not having my child,” he said.

Johnson said he swung the machete and hit her left temple.

As his rage subsided, Johnson commenced a weeks-long scheme to cover up the killing by reporting her as a missing person. He was aware that the dumpster used by his unit at Schofield Barracks was emptied directly into an incinerator, which would leave no trace of her body.

Johnson tried dismembering her body with the machete, “but it was too much hassle,” he said.

“The next day I got the chainsaw and cut off her arms, her legs, and I left the torso and head,” he said.

For the rest of July, Johnson said he continued to text his wife’s family and friends using her phone. He posed as her on social media and kept up conversations with her contacts.

He also removed items of her clothing, makeup and jewelry so investigators would believe his story that she was distraught and simply walked away.

Johnson, of Frederick, Md., is a cavalry scout with the 25th Infantry Division, where he was assigned in June 2023. He will receive a dishonorable discharge as part of the plea agreement.