CENTENNIAL, Colo. -- An Arapahoe County man convicted of murdering his 6-year old son and raping his ex-girlfriend will spend life in prison.
Twenty-eight-year old Brandon Johnson's guilty plea and immediate sentence Friday morning allowed him to avoid the death penalty.
Johnson was originally facing the death penalty after being charged with First Degree Murder, Child Abuse Resulting in Death, Sexual Assault, Felony Menacing and Domestic Violence.
Arapahoe County Sheriff Deputies were dispatched to an apartment in the 7500 block of E. Harvard Avenue on Feb. 10, 2016 after responding to a 911 call about a rape.
After deputies arrived they learned Johnson had raped his ex-girlfriend at knife point inside their apartment.
He did not harm the couple's 2-year old son but after the woman ran next door to call 911, he slit the throat of his 6-year old son Riley from a prior relationship and then slashed his own throat.
At his sentencing, Johnson spoke with a muffled voice because his vocal cords have been permanently damaged. He apologized to his victims and his family saying, "You have been hurt by my inexcusable actions."
Arapahoe County District Attorney George Brauchler said he remains conflicted about taking the death penalty off the table considering the severity of Johnson's crimes, "You ask people 'what is justice for someone that would mercilessly slit the throat of their 6-year old boy?' and I'm pretty sure life in prison isn't the only answer they could up with."
But Brauchler said he agreed to the plea deal after receiving mental health records from the defense that showed Johnson had a history of depression that included homicidal and suicidal thoughts.
"He believed in his depressed state that his life was not worth living and in that state of mind, he was terrified that his son would be left behind in a loveless world," said Johnson's public defender Stephen McCrohan.
The mother of 6-year-old Riley Johnson attended the sentencing but declined to speak with the media afterwards.
The ex-girlfriend of Johnson, who is the mother of his 2-year old boy, refused to sit in the same courtroom with him.
She was allowed to watch the proceedings on closed circuit TV from another courtroom.