On this appeal from appellant’s conviction on two counts of uttering a forged instrument, appellant claims he should be discharged because he was not brought to trial within the period prescribed by the speedy trial rule, Fla.R.Crim.P. 3.191. We agree. The State’s contention is that the period of the rule did not begin to run until August 25, 1978, when appellant was formally arrested on the charges of which he is now convicted. We find, on the contrary, that the period began to run on August 4, 1978, when appellant was taken into custody as a suspect on these and related charges, was advised of his constitutional rights, and was interrogated. Appellant then confessed to these and related charges. Appellant was then in custody on all those charges, though he was then formally arrested on only one of them, which subsequently was dismissed. See State v. N. B., 360 So.2d 162 (Fla. 1st DCA 1978), cert. *44dismissed, 365 So.2d 713 (Fla.1978); Deloach v. State, 338 So.2d 1141 (Fla. 1st DCA 1976).
The convictions are REVERSED and appellant is DISCHARGED.
ERVIN and WENTWORTH, JJ., concur.