Defendant brings forward five assignments of error. Defendant’s first three assignments of error are directed to the admission into evidence of the marijuana seized from his person. Defendant contends that the evidence was inadmissible because (i) the initial stop of defendant’s vehicle was unconstitutional, (ii) defendant’s arrest was unconstitutional, and (iii) the search of defendant’s person and the seizure were unconstitutional in that they were the products of the illegal detention. Defendant’s fourth assignment of error is that the trial court erred in denying his motion to dismiss the charges against him. His fifth assignment of error is that the trial court erred in accepting the verdicts of the jury.
*332 [1] By his first three assignments of error, defendant challenges the admissibility of evidence on the grounds that it was obtained in violation of his constitutional rights. The exclusive method of making such a challenge at trial is by a motion to suppress made in compliance with the requirements of Chapter 15A of the General Statutes. State v. Harris, 71 N.C. App. 141, 142, 321 S.E. 2d 480, 482 (1984). In this case, the trial court summarily denied defendant’s motion to suppress..
Subject to well-defined exceptions, a motion to suppress must be made prior to trial. G.S. 15A-975. Defendant has not shown that he comes within an exception to the general rule, and he not only failed to make his motion prior to trial but also failed to make it before the evidence was admitted. Because defendant’s motion was not timely, the trial court could properly summarily deny the motion. State v. Satterfield, 300 N.C. 621, 625, 268 S.E. 2d 510, 514 (1980). Failure to make a proper motion to suppress constitutes a waiver of the right to challenge the admissibility of evidence on constitutional grounds. Id. at 624, 268 S.E. 2d at 513.
[2] Although defendant has waived his right to challenge the admissibility of the evidence that was seized from his person, we must nevertheless determine whether defendant’s detention was illegal. Defendant’s fourth assignment of error raises the issue of whether the trial court erred in failing to dismiss the charge of resisting a public officer. If the officers in this case acted illegally, then defendant was entitled to resist them and the motion to dismiss the charge should have been granted. State v. McGowan, 243 N.C. 431, 90 S.E. 2d 703 (1956); State v. Hewson, 88 N.C. App. 128, 362 S.E. 2d 574 (1987).
Defendant contends that his arrest was illegal because the officers attempted to arrest him under a warrant for the arrest of another individual and there was no probable cause to arrest defendant. The conduct proscribed under G.S. 14-223 is not limited to resisting an arrest but includes any resistance, delay, or obstruction of an officer in the discharge of his duties. The indictment in this case alleges that defendant attempted to run from and struggled with the officers while they were attempting to ascertain defendant’s identity. Thus, defendant’s conviction may be based upon his conduct prior to the time of his actual arrest. Cf. State v. Davis, 90 N.C. App. 185, 190, 368 S.E. 2d 52, 56 (1988) (dismissal required where indictment alleged post-arrest resistance and evi*333dence showed pre-arrest resistance). Therefore, we must examine the officers’ conduct from the moment they first stopped defendant’s vehicle.
Defendant contends that the initial stop of his vehicle was illegal. The officers stopped the vehicle for the purpose of ascertaining defendant’s identity. A brief detention of an individual for this purpose is not an arrest but is, however, considered a seizure of the person subject to the requirements of the fourth amendment to the United States Constitution. Brown v. Texas, 443 U.S. 47, 99 S.Ct. 2637, 61 L.Ed. 2d 357 (1979). The fourth amendment requires that, in order to detain an individual, the police must have a reasonable suspicion of criminal activity based upon known and objective facts. Id. See also State v. Williams, 87 N.C. App. 261, 360 S.E. 2d 500 (1987). The suspicion need not concern ongoing criminal activity, but may relate to the individual’s involvement in a past crime. United States v. Hensley, 469 U.S. 221, 229, 105 S.Ct. 675, 680, 83 L.Ed. 2d 604, 612 (1985).
In this case, Officer Pipkin testified that he mistakenly believed that defendant was another individual for whom arrest warrants had been issued. Pictures of defendant and the other individual show that they are sufficiently similar in appearance that the officer’s mistake was not unreasonable. The United States Supreme Court has held that an arrest based upon a reasonable mistake as to the arrested individual’s identity is valid. Hill v. California, 401 U.S. 797, 91 S.Ct. 1106, 28 L.Ed. 2d 484 (1971). Under the facts of this case, we need not decide whether the officer’s initial mistake justified an arrest; it was at least sufficient to establish a reasonable basis to stop defendant and require him to identify himself. When an officer is unsure of the identity of a suspect, he must take reasonable steps to confirm the identity of the individual under suspicion. United States v. Glover, 725 F. 2d 120, 123 (D.C. Cir.), cert. denied, 466 U.S. 905, 104 S.Ct. 1682, 80 L.Ed. 2d 157 (1984). See also Robinson v. City of Winston-Salem, 34 N.C. App. 401, 406-07, 238 S.E. 2d 628, 631 (1977) (same duty imposed upon officers in civil action for false imprisonment).
In the present case, the officers were lawfully discharging a duty of their office when they asked defendant to identify himself. Once they did so, defendant attempted to flee. Because defendant had not identified himself, the officers had no choice but to apprehend him in order to ascertain his identity. Defendant continued *334to refuse to identify himself after his arrest, and the officers testified that they still believed him to be the other individual up to the time that they discovered drugs on his person.
Defendant’s reliance on State v. Williams, 32 N.C. App. 204, 231 S.E. 2d 282, appeal dismissed, 292 N.C. 470, 233 S.E. 2d 924 (1977), is misplaced. In Williams, this Court held that a defendant’s flight from an unlawful attempt to arrest him was justified and could not be considered as a circumstance to establish probable cause for the arrest. Id. at 208, 231 S.E. 2d at 284-85. In this case, however, defendant fled from a lawful investigatory stop. Such flight may provide probable cause to arrest an individual for violation of G.S. 14-223. See State v. McNeill, 54 N.C. App. 454, 456, 283 S.E. 2d 565, 567 (1981).
We need not determine whether mere flight after an officer’s request for identification is sufficient to sustain a conviction under G.S. 14-223. The State’s evidence in this case shows that defendant continued to struggle after the officers apprehended him. For the purpose of ruling on a motion to dismiss, this evidence must be viewed in the light most favorable to the State. State v. Brown, 310 N.C. 563, 566, 313 S.E. 2d 585, 587 (1984). We find the evidence in this case to be sufficient to sustain defendant’s conviction for resisting a public officer.
Defendant also contends that the trial court erred in failing to dismiss the charge of possession of marijuana with intent to sell or deliver. This contention is based upon defendant’s prior arguments concerning the admissibility of the drugs seized from his person. Having held that defendant waived his right to challenge the admissibility of the evidence, we find no error in the trial court’s denial of defendant’s motion to dismiss the charge.
Defendant offers no additional arguments in support of his fifth assignment of error. Accordingly, the assignment is overruled.
For the foregoing reasons, we find that defendant’s trial was free of reversible error.
No error.
Judges Phillips and Cozort concur.