I would suggest that you need to look at your Recruitment and Selection process. If I understand the underlying message in your posting, you do not appear to have a robust recruitment process in place. That is not recruitment. I have posted here many times on this subject. Here again is Aussiejohn's 6 Easy Steps to Recruitment and Selection.
Aussiejohn's 6 Easy Steps to Recruitment and Selection
If you want the right candidate for the job, you only need 6 things:
1. A proper position description which sets out the requirements of the job.
2. A person specification setting out what the successful candidate needs to perform the job.
3. A rigorous selection process based on the PD and PS, to choose the top 4 candidates to interview.
4. A targeted interview questionnaire based on the PD and PS, to ensure the candidates can do the job and can integrate into the company—no stupid, irrelevant questions that have nothing to do with the job.
5. Well-trained interviewer/s.
6. A rigorous reference checking process.
Place well-worded advertisements or work with a trusted employment agency who will source the RIGHT type of candidates for interview. That's all there is to it. No need to complicate the process. Remember the KISS principle.