Five months to the day after her daughter disappeared while attending a Metallica concert at the John Paul Jones Arena in Charlottesville, Morgan Harrington's mom wrote a soul-baring account of her feelings, saying a "sadistic monster" is walking free.

Morgan, a 20-year-old Virginia Tech student, vanished October 17 after leaving the concert at the JPJ.

Her body was found in January in an isolated spot on Anchorage Farm, a few miles south of Charlottesville. Police say she was murdered but have made no arrests and have offered little new information about the crime or its investigation in the following weeks.

On her blog, Gil Harrington wrote:

"The nights can be difficult. When you are between sleep and wake your defenses dip and then unwanted thoughts and images come roaring in. I try not to think of how scared you were, the terror you felt. I try not to think of how much pain you were in as you were slaughtered.

"Were you still alive when they brought you to Anchorage Farm? To be hunted like a deer running frantically over the hay stubble in the field desperate to escape, trying to survive, crying, screaming, I see it. I hear it. Or, were you brought there already dead, like a slab of meat, carrion to be discarded and dumped in the field to rot - just another carcass in the hunting preserve.

"These images haunt me at night. During the day I can usually shake them off and focus on our job, trying to find your murderer. Other girls are in danger while this sadistic monster walks free. We will never rest until he is put away. Morgan will you help us, in what ever way you can to remove his evil from the world?"

Morgan's parents also aired frustrations Wednesday. Dan and Gil Harrington say they're upset with how long it's taking to get DNA results from the Office of the medical examiner.

They also expressed frustration with the JPJ, saying little has been done to improve security since Morgan's death.