A teenager charged with the stabbing and strangling death of his mother has entered into a plea bargain.

Lukas Mironovas, 16, entered the guilty plea on a charge of murder Wednesday in a Kennebec County court. He was charged with the 2018 killing 47-year-old Kimberly Mironovas.

A lawyer for Lukas Mironovas says the deal will result in a prison term of 25 to 35 years. He could have faced a life sentence without the plea agreement.

Prosecutors have said Mironovas and two friends planned to spike his mother’s drink with crushed prescription pills. When that plan failed, they decided to strangle and stab her.

One of the two other teenagers faces trial as an adult, while the other has been sentenced to juvenile detention.