A criminal record in Spain from 30 years ago can be stricken from the record. This includes the 'verbal warning' your husband received about never returning to Spain. Under any given scenario, your husband's record can be considered 'spent' if a procedure is followed. "Spent" is a legal term meaning that the period of rehabilitation has been completed and the individual is entitled to deny a prior conviction.

For authority on this we can turn to the Law Commission, which maintains a page on rehabilitation in other jurisdictions. There is an entry for Spain which says (in part)...

There is a right to “cancellation” of criminal records in Spain, which can be sought in two ways. Neither route to cancellation is automatic.

You can read the details at DISCLOSURE OF CRIMINAL RECORDS INFORMATION IN OTHER JURISDICTIONS.

It may be worth the effort just to clear the air and let them come back with a reply that there is no record to expunge. This would be the case if your husband contemplated future travel to the EEA and didn't want the anxiety . This strategy is the one that provides absolute certainty.

You can do this concurrent to the EU transparency rules and see which takes longer, but note that receiving info from the EU does not clear anything from his record or provide him with a visa, it is info only and they may opt to refuse the information request anyway.

For a one-off trip to Europe, my comment about obtaining a Schengen visa stands as 'best practices' because it avoids wasted airfares and the distress of removal from port.

Note that in all events your husband will still need to qualify as a short-stay visitor.

For the part about asking for your husbands alerts under the EU transparency regulations, data retention comes in to play in a way that may be beneficial to him. Regulation (EC) No 1987/2006 has this to say...

Alerts for the purpose of refusing entry or stay should not be kept longer in SIS II than the time required to fulfil the purposes for which they were supplied. As a general principle, they should be automatically erased from SIS II after a period of three years. Any decision to keep an alert for a longer period should be based on a comprehensive individual assessment. Member States should review these alerts within this three-year period and keep statistics about the number of alerts the retention period of which has been extended.

Spain joined the Schengen regime in 1991, 4 years after your husband's (alleged) offence. If they entered an alert at that time it would have expired in 1994. Otherwise we have to accept the palpably ridiculous case that they entered an alert in 2015 for an offence that occurred in 1987 and for which there were no judicial proceedings and no indications in his passport. Biometrics did not exist in a real way until the mid 2000's and this further removes the likelihood of a problem.

Note that in all events your husband will still need to qualify as a short-stay visitor.

A criminal record in Spain from 30 years ago can be stricken from the record. This includes the 'verbal warning' your husband received about never returning to Spain. Under any given scenario, your husband's record can be considered 'spent' if a procedure is followed. "Spent" is a legal term meaning that the period of rehabilitation has been completed and the individual is entitled to deny a prior conviction.

For authority on this we can turn to the Law Commission, which maintains a page on rehabilitation in other jurisdictions. There is an entry for Spain which says (in part)...

There is a right to “cancellation” of criminal records in Spain, which can be sought in two ways. Neither route to cancellation is automatic.

You can read the details at DISCLOSURE OF CRIMINAL RECORDS INFORMATION IN OTHER JURISDICTIONS.

It may be worth the effort just to clear the air and let them come back with a reply that there is no record to expunge. This would be the case if your husband contemplated future travel to the EEA and didn't want the anxiety . This strategy is the one that provides absolute certainty.

For a one-off trip to Europe, my comment about obtaining a Schengen visa stands as 'best practices' because it avoids wasted airfares and the distress of removal from port. Should your husband opt for this strategy, he may wish to consider applying for a transit visa instead, there were not enough particulars in your question to know if this is a viable strategy or not.

Note that in all events your husband will still need to qualify as a short-stay visitor.

A criminal record in Spain from 30 years ago can be stricken from the record. This includes the 'verbal warning' your husband received about never returning to Spain. Under any given scenario, your husband's record can be considered 'spent' if a procedure is followed. "Spent" is a legal term meaning that the period of rehabilitation has been completed and the individual is entitled to deny a prior conviction.

For authority on this we can turn to the Law Commission, which maintains a page on rehabilitation in other jurisdictions. There is an entry for Spain which says (in part)...

There is a right to “cancellation” of criminal records in Spain, which can be sought in two ways. Neither route to cancellation is automatic.

You can read the details at DISCLOSURE OF CRIMINAL RECORDS INFORMATION IN OTHER JURISDICTIONS.

It may be worth the effort just to clear the air and let them come back with a reply that there is no record to expunge. This would be the case if your husband contemplated future travel to the EEA and didn't want the anxiety . This strategy is the one that provides absolute certainty.

You can do this concurrent to the EU transparency rules and see which takes longer, but note that receiving info from the EU does not clear anything from his record or provide him with a visa, it is info only and they may opt to refuse the information request anyway.

For a one-off trip to Europe, my comment about obtaining a Schengen visa stands as 'best practices' because it avoids wasted airfares and the distress of removal from port.

Note that in all events your husband will still need to qualify as a short-stay visitor.