On the fifth anniversary of the disappearance of Zoe Campos, a man is charged with her murder.

An arrest warrant was issued early Saturday for Carlos Rodriquez, 25. He was already in custody, awaiting transfer for a four-year prison sentence on a stalking conviction.

Human remains were found in a south Lubbock backyard, Police Chief Greg Stevens announced late Friday night. Investigators have been at the home in the 1900 block of 70th Street for the past several days, acting on new information in the search for Campos.

The remains have not yet been positively identified; this is expected in a few days. "A lot of work will have to be done through the Medical Examiner's Office and some forensic work to determine who those remains belong to," Stevens said. But, he added, considering the circumstances and information gathered, everything leads them to believe this is Zoe.

Stevens also said a bone discovered last week in another part of the back yard is not human.

"This investigation has taken a number of different directions."

Watch Stevens' Friday night update in this video:

Detectives brought an inmate to the scene Friday to provide information. Police have yet to confirm if this inmate was Rodriquez.

Detectives were also on horseback earlier this week scouring a field near 66th Street and Interstate 27. There was no information on what prompted the field search or whether anything was found.

A search warrant was issued for police to search the 70th Street home and property, looking for "blood evidence, trace evidence and human remains".

Zoe Campos was 18 at the time of her disappearance. Her mobile phone pinged within a mile of Lowrey Field that night. Both the 70th Street home and the field off the interstate are within a mile of that cell tower. There hasn't been a trace of her since.

Many law officers and volunteers have spent tireless hours on this case, looking for leads. There may still be helpful information out there. You can anonymously provide tips to police by calling CrimeLine at 806.741.1000.

"There's still a lot of work to be done," Stevens said Friday night. "Still a large crime scene to process. That'll carry on through the weekend and into next week."

Stay with FOX34 News for updates on this developing story.