Long

I

This case concerns the constitutional propriety of a police officer’s direction that a lawfully detained criminal suspect produce identification. We determine that under the circumstances, the production of identification was lawfully required.

Defendant Frederick Long was convicted by his guilty plea of possession of methamphetamine. (Health & Saf. Code, § 11377, subd. (a).) He now seeks reversal of the judgment, claiming erroneous denial of his motion to suppress the evidence of his guilt. (Pen. Code, § 1538.5, subd. (m).) We affirm the judgment but remand for redetermination of presentence credits.

II

The Facts

On February 20, 1985, at about 10 p.m., veteran San Jose Police Officer Dennis Luca and trainee Brian Blackford were in uniform conducting a premises check of a bar. Officer Luca noticed defendant conversing with a young woman by a pool table. The woman appeared underage. Defendant was drinking beer. The girl was not seen drinking, but there was an empty cocktail glass near defendant’s beer bottle.

Blackford contacted the girl to ask her age. Within a minute, Blackford signaled Luca to come over, because the woman indicated she was 19 years old.…