A Maine man who pleaded guilty to killing the mother of his three children is challenging his conviction.

Anthony Leng pleaded guilty in 2019 as part of a plea deal to avoid a trial. He was sentenced to 40 years behind bars for the death of his partner, 36-year-old Sokha Khuon.

Leng acknowledged shooting Khuon in 2018, telling police he acted out of fear when she turned to him with a knife.

A conviction challenge was scheduled for Wednesday morning in Portland.