I think this should be taken as a good sign!
If it is a telephone interview, I would prepare by doing the following:
Make sure you have good internet / technological / telephone access to make sure there are no glitches during the interview. Can you test the system when you get there?
Make sure you have a quiet and private space in which to conduct the interview.
Make key notes, so if you stumble or need to pause to gather your thoughts, the important bits are to hand.
Like any interview:
Make sure you get rest and eat well and have a decent outfit to boost your confidence. Make sure you have water with you.
What about volunteering in a related field, prior to the interview, to boost your application?
http://ww2.prospects.ac.uk/p/types_of_job/forensic_psychologist_prison_and_probation_services_entry_requirements.jspYou could also read on a specific topic of interest in forensic psychology in online e- journals. You must still have university access for this at your current uni?
What about the ideas here regarding personal statements:
http://www.kent.ac.uk/careers/postgradmenu.htm'Possible content for your statement
Why do you want to do the course/research?
Try to convey your enthusiasm and motivation for study/research. Don't try to write what you think they want to hear, write your real reasons. Write about any projects dissertations or extended essays you have done if they are relevant or demonstrate relevant skills. Mention any prizes you have won, also travel or study abroad and relevant employment. Describe anything that shows creativity, dependability or independence.
Why this subject?
Be clear about why you have chosen this. Is the programme noted for a particular emphasis, speciality or orientation? When did you become interested in this field and what have you learned about it? What insights have you gained? How have you learned about this field - through classes, seminars, work or conversations with academic staff?
Why this university?
Be specific – don’t make bland statements such as “Because you are an internationally-renowned university with an excellent academic reputation”. Is the programme noted for a particular emphasis, speciality or orientation? Are there specific academic staff you want to do research or study with? What is it about the structure of the course, or the choice of modules, that appeals to you?
What academic skills have you got to offer?
Computing skills, knowledge of relevant scientific techniques etc. If your A levels were poor (or you didn't do these, try to show an upward progression during your time at University).
In general the best candidates (for postgraduate funding)
had read and followed the guidelines and provided the information sought
expressed their proposed project convincingly
avoided jargon and aimed to make their statement intelligible to readers with expertise in the general subject area, but not necessarily in the specific area of their proposed research
were able to make a convincing case about the significance of the proposed topic, and show evidence of wide reading around the subject.
Arts and Humanities Research Board
What personal skills can you offer? e.g. ability to work in a team, with little supervision.
Demonstrate that you've done your homework about the course/research and that you've seriously considered your strengths and weaknesses for postgraduate study or research. If you have done vacation jobs, what skills have you learned: teamworking, communication, working under pressure? Have you had to overcome any obstacles or hardships in your life? This may show evidence of determination/resilience.
What are your strengths?
In what ways are you better than other applicants? If you can't answer this question, don't expect the selectors to answer it for you!
What is the relevance of your first degree to this study?
Point out any circumstances that may have effected your academic results, that you think should be considered by the selectors.
What are your career aims?
You may not have a very clear focus on what you want to do afterwards, but you should have some ideas. A clear direction will strengthen your commitment to do well in your studies and selectors will know this. Your desire to become a lawyer, lecturer, or whatever should be logical, the result of specific experience in your statement.'
Hope that helps and good luck.