According to authorities in Heber Springs, Ark., country singer Mindy McCready's cause of death has been confirmed as suicide. Preliminary autopsy results indicate the 'Ten Thousand Angels' singer died as a result of a single self-inflicted gunshot wound to the head.

The 37-year-old died on Sunday (Feb. 17), just a month after her boyfriend, music producer David Wilson, was found dead at the same Arkansas home where McCready was later found. He also died from a gunshot wound, but authorities have not yet ruled his death a suicide. McCready was reportedly being investigated for her possible role in his death, which she vehemently denied the week before she killed herself.

Cleburne County Sheriff Marty Moss told E! News that McCready did not leave a suicide note, and her death is still the subject of an ongoing investigation. She did, however, record a song called 'I'll See You Yesterday' prior to her death that is believed to be a message.

Moss declined to reveal whether Wilson had left a suicide note.

McCready left behind two sons; 6-year-old Zander, and 10-month-old Zayne, her son with Wilson. The custody of both boys will be determined at a hearing set for April 5.