"Guilty party/parties" is fine. I have no idea what a "house detective" is.
The people employed by shops to look out for shoplifters are called "store detectives". In the UK, we don't have a specific police or security department who are tasked with looking out for people burgling houses. There might be a "burglary team" at a police station but they probably deal with the aftermath of a burglary, they don't walk the streets looking out for people burgling houses.
What exactly did you mean by "house detective"?
Student or Learner