I have report a crime to the Guardia Civil.
A friend was sailing in a small boat to USA. He got an email to say that his father's car (father was at the time in UK) had been stole from in front of his house. No problem with me making the report.
Although not all crimes can be reported, a burglary, theft, criminal damage etc. can be reported on 902 102 112, in English, and then signed at any National Police Station. The report will be in Spanish and depending on your clarity of speech, and the interpreter’s ability, it can be a correctly written report.
But be aware. In Spain one cannot make a crime report anywhere but in a police station, i.e. not to a police officer who attends a crime scene,
In addition, of course one can report a crime which has been committed in Spain (or anywhere) to the police in the UK. It will then be forwarded via INTERPOL. You may find that the officer at the desk is not aware that you can but if you have a problem insist that officer contacts a senior officer for advice. I have arranged for a man in Wales to report a burglary in Spain in that way.