Locks can be easily picked, even by amateurs. Cheap lock pick tool kits are sold online. There are also lessons online that teach how to pick locks. I have no idea about the position of Harley's remains found in the chimney. Feet down or up? Nor do I know what was on the second floor. A completely sealed wallboard wall in relation to the chimney? An open elbow vent (flue)? If open, birds and squirrels could gain access into the home. IMO, LE is not releasing some relevant information. It is very possible that Harley was a murder victim. I still think about Damian Henning from Norwalk, Ohio who vanished from Kalahari, south of Sandusky, Ohio. His body was found two days later under a high level bridge in Toledo, Ohio. LE and the coroner ruled his death a suicide. I do not believe it due to LE sloppy investigation, ignoring surveillance videos, clues and forensic evidence. Damian's mother has a Facebook page that is public and she details her issues with LE. Her last name is Jackson.
Wow, I hadn't heard of Damian's case. That does sound suspicious.
Henning's mother struggles with answers
Pt. Clinton & Sandusky areas are hot tourist spots in the summer. Public officials may not want to cause problems.
ETA: MOO I don't think Harley's death was suspicious at this point in time, but Damian's does look unusual.