A criminal investigation has been launched into the death of a 30-year-old Illinois woman whose body was discovered near some railroad tracks after she had been missing for three days.

MeLisa Cleary's body was found by railroad workers near Hartsburg on Monday and positively identified on Tuesday, said Tazewell County prosecutor Stu Umholtz.

The corpse showed obvious signs of trauma, according to Logan County Coroner Robert Thomas.

Cleary vanished Friday afternoon. Family members said they found her vehicle a couple of miles from her home along Route 9.

Her estranged husband Daniel Cleary took the couple's three children on Monday, but authorities found them Tuesday at a Peoria motel, hours after an Amber Alert was issued.

Umholtz said the children are now in the custody of a relative.

No one has been taken into custody, according to Umholtz.

On Tuesday, authorities questioned Daniel Cleary, but they declined to elaborate.

The Associated Press contributed to this report.