Welcome to EH-Net, daydream.

There are several possibilities to get into a security job. First off I would "sell" your 10 years of experience as a developer and sysadmin as good as possible. So even if you did little security tasks within your job, you can bring it up - managing all computers to be up-to-date, configuration according to certain policies etc.; Even if it first doesn't seem really relate to security, it might do for a job interviewer. So try to write down all possible tasks you had to do within your jobs and empathize them to security, administration etc.
There are some other things as well you could do - e.g. aim for certificates (entry level ones would be for example Security+ by CompTIA and CEH by EC-Council), start a website/ blog about something which interests you very and include it in your CV, contribute to one of the dozens projects already available or start one of your own (if you worked as a developer it shouldn't be too hard ).
Additionally you could write articles for magazines or meet up with security groups in your area.

Another thing I would recommend is to not only search for already available job offerings, but to just write an application to whatever company interests you. Very often, even if there was no job opening, you will be invited to a job interview. If you found a company which really interests you, you could also first write to some other companys and use their invitation to train you skills in job interviews in order to get better prepared for the one you are really interested in.

As you can see, there are some things one can do and certainly I listed only a few of the common ones.