He was taken to hospital, as investigators obtained his fingerprints as well as a search warrant for his home.
Returning to the apartment, police found a suitcase that matched the one from the crime scene, as well as a bloody saw blade.
Using luminol, they also found blood stains all over the couch, bathroom and in the bathtub.
Lockard, who had reportedly struggled with meth addiction and had recently been kicked out of a rehab facility, was last seen alive on December 26. A friend told detectives he had dropped him off at Alameda High School around noon, after giving him a ride to cash a check.
Surveillance footage shows Satterthwaite buying a saw from Walmart on December 27.
From the arrest affidavit, seen by Denver 7 News, it appears that the suspect and the victim knew each other, and that the latter had stayed at the former's apartment previously. However no motive for the killing was given.
Satterthwaite has been charged with one count of murder in the first degree, and one count of tampering with a deceased human body.