¶1The single issue presented is whether Tolbert’s conviction on the lesser included offense prevents the state from later prosecuting him on the greater offense because of the protection against double jeopardy of the Fifth Amendment to the United States Constitution. For the reasons that follow, we answer such query in the negative.
¶2In Benton v. Maryland (1969), 395 U.S. 784, 794, the United States Supreme Court held that the Fifth Amendment guarantee against double jeopardy*
¶3The United States Supreme Court in Blockburger v. United States (1932), 284 U.S. 299, 304, recognized that the Double Jeopardy Clause of the Fifth Amendment prohibits successive prosecutions for the same criminal act or transaction under two criminal statutes unless each statute “requires proof of a fact which the other does not.”
¶4In deciding whether the state was precluded from charging a defendant with involuntary manslaughter of a robbery victim subsequent to the defendant’s conviction for the robbery, this court in State v. Thomas (1980), 61 Ohio St. 2d 254, 261, 15 O.O. 3d 262, 266, 400 N.E. 2d 897, 903, set forth a two-part double jeopardy inquiry:
¶5“… One is whether the offenses of robbery and involuntary manslaughter are distinguishable under the Bbckburger standard; i.e., do[es] each of the crimes of robbery and involuntary manslaughter require proof of a fact which the other does not?
¶6“Two, there being a less serious offense for which the defendant has been previously tried, is the state prohibited from relitigating the factual issues already resolved in the prior trial, or do the facts of this case present an exception to the general rule prohibiting multiple prosecutions?”
¶7The exception referred to in Thomas, supra,originated in Diaz v. United States (1912), 223 U.S. 442, where the Supreme Court recognized an exception to a double jeopardy statute by holding that a defendant’s conviction of assault and battery did not prevent a subsequent prosecution for homicide after the death of the victim. The Supreme Court, in Brown v. Ohio, supra,found the constitutional exception to “exist where the State is unable to proceed on the more serious charge at the outset because the additional facts necessary to sustain that charge have not occurred or have not been discovered despite the exercise of due diligence.” Id. at 169, fn. 7; accord Grady v. Corbin, supra,at_, 109 L. Ed. 2d at 561, 110 S. Ct. at 2090, fn. 7; Ashe v. Swenson, supra, at 453, fn. 7 (Brennan, J., concurring) (“where a crime is not completed or not discovered, despite diligence on the part of the police, until after the commencement of a prosecution for other crimes arising from the same transaction, an exception to the ‘same transaction’ rule should be made to permit a separate prosecution.”).
¶8In the case sub judice, the first inquiry is whether the offenses of misdemeanor assault and felonious assault *92are distinguishable under the Block-burger standard (do both require proof of a fact which the other does not?). The offense of misdemeanor (or simple) assault is a violation of R.C. 2903.13, which provided
¶9“(A) No person shall knowingly cause or attempt to cause physical harm to another.
¶10“(B) No person shall recklessly cause serious physical harm to another.
¶11“(C) Whoever violates this section is guilty of assault, a misdemeanor of the first degree. …” H.B. No. 511, 134 Ohio Laws, Part II, 1866, 1902.
¶12The offense of felonious assault (as charged in this case) is a violation of R.C. 2903.11, which specifies:
¶13“(A) No person shall knowingly:
¶14“(1) Cause serious physical harm to another[.]
¶15…
¶16“(B) Whoever violates this section is guilty of felonious assault, an aggravated felony of the second degree. …” ’
¶17It is conceded by the parties that misdemeanor assault is a lesser included offense of felonious assault. Thus, the greater offense, felonious assault, is by definition the same for purposes of double jeopardy as the lesser included offense, misdemeanor assault. See Brown v. Ohio, supra, at 168. Consequently, the two offenses are indistinguishable under the Blockburgerstandard.
¶18Although the two offenses are the same for purposes of double jeopardy, we must still determine whether the facts in this instance invoke the exception to the general rule. As we stated in Thomas, supra, at 261, 15 O.O. 3d at 266-267, 400 N.E. 2d at 903, this “second query depends upon the circumstances existing at the time of the first trial. [And] [t]he reviewing court may determine whether all the actionable facts had come into being or, conversely, whether there were later occurrences which had emanated from the initial conduct …
¶19In the present case Hildebrand testified that the day after the assault took place, and only hours after the defendant pled no contest to a lesser offense, the police were first informed that Ochs’s injuries may have been more severe than first indicated. Until Ochs was evaluated by her own physician she had no way to confirm the extent of her injuries. In fact, Ochs’s diagnosis was not final until a week after she was attacked. Therefore, even though the facts necessary to sustain the charge of felonious assault occurred prior to Tolbert’s plea, these facts were not discoverable despite the exercise of due diligence. See Brown v. Ohio, supra, at 169, fn. 7.
¶20Accordingly, for the foregoing reasons, the judgment of the court of appeals is reversed, and the cause is remanded for proceedings not inconsistent with this opinion.
¶21Judgment reversed and cause remanded.
¶22 The Double Jeopardy Clause of the Fifth Amendment to the United States Constitution states: “[N]or shall any person be subject for the same offence to be twice put in jeopardy of life or limb.”
¶23 The Blockburgertest emphasizes the elements of the two crimes. Essentially, “[i]f each requires proof of a fact that the other does not, the Blockburgertest is satisfied, notwithstanding a substantial overlap in the proof offered to establish the crimes. …” Iannelli v. United States (1975), 420 U.S. 770, 785, fn. 17.
¶24 In Broun the defendant stole an automobile and was caught several days later and charged with “joyriding” — taking or operating the car without the owner’s consent. Defendant pled guilty *91and was sentenced to thirty days in jail and a one-hundred-dollar fine. Id. at 162. After his release from jail Brown was indicted on two counts, charging him with the original theft of the car and joyriding on the same date of the theft. Brown objected to the counts on double jeopardy grounds. Id. at 163. The Browncourt decided that Brown could not be convicted of either of the charges since they were the same offense under the Double Jeopardy Clause as the one he had pled guilty to. The court noted that “[t]he Double Jeopardy Clause is not such a fragile guarantee that prosecutors can avoid its limitations by the simple expedient of dividing a single crime into a series of temporal or spatial units.” Id. at 169.
¶25 Subsequent to the assault in this case, R.C. 2903.13(C) was amended by H.B. No. 642, 142 Ohio Laws, Part III, 4696, 4698-4699.