
314 S.E.2d 268 (1984)
STATE of North Carolina
v.
Tommy Franklin ESSICK.
No. 8322SC787.
Court of Appeals of North Carolina.
April 17, 1984.
*270 Atty. Gen. Rufus L. Edmisten by Asst. Atty. Gen. Michael Rivers Morgan, Raleigh, for the State.
Smith, Michael & Penry by Robert B. Smith, Jr., Lexington, for defendant-appellant.
EAGLES, Judge.

I.
Defendant's first three exceptions and assignments of error raise evidentiary questions. For the reasons stated below, we find no error.

A.
The defendant assigns as error that the prosecution failed to lay a proper foundation for admission into evidence of testimony by Detective Sammy Hampton that he saw marijuana in the trunk of the car that had been operated by Troy Melton. The basis for defendant's contention is that Detective Hampton was not properly qualified to give an opinion that the "vegetable type material" which he observed "appeared to be marijuana."
Determination that a witness possesses the requisite skill to testify as an expert is a question of fact generally within the exclusive province of the trial court. State v. King, 287 N.C. 645, 658, 215 S.E.2d 540, 548 (1975), State v. Young, 58 N.C.App. 83, 87, 293 S.E.2d 209, 212 (1982). Further, where there is evidence of qualification, the trial court's decision to permit one to testify as an expert is tantamount to holding him to be an expert in the field of his testimony. State v. Moore, 245 N.C. 158, 95 S.E.2d 548 (1956). Detective Hampton testified at trial that he had been employed by the sheriff's department for three and a half years and at the time of the criminal offense he was on a special drug case assignment. We conclude that there was no abuse of discretion by the trial court and that based on Detective Hampton's experience, he was better qualified than the jury to form an opinion on the subject matter to which he testified. State v. Phifer, 290 N.C. 203, 213, 225 S.E.2d 786, 793 (1976).

B.
Defendant assigns as error that the prosecution failed to establish a connected chain of custody in order to permit proper introduction of the bags of marijuana into evidence. He bases this contention on the use of such phrases as "to the best of my knowledge" and "as far as I know." These phrases were used by the testifying officers when asked whether any persons other than themselves had access to the evidence locker. The fact that officers other than those who gathered and sealed the *271 evidence may have had access to the evidence locker does not destroy the chain of custody. State v. Newcomb, 36 N.C.App. 137, 243 S.E.2d 175 (1978). There was no testimony that any tampering with the evidence occurred. We therefore conclude that the evidence is properly admissible.

C.
The defendant further argues that the trial court erred in denying his motions to dismiss based on the State's failure to present sufficient evidence of conspiracy to submit the case to the jury or to sustain the jury's verdict.
A motion to dismiss in a criminal case requires the court to weigh all of the evidence in the light most favorable to the State and the State is entitled to all reasonable inferences that arise from the evidence. State v. Fletcher, 301 N.C. 709, 272 S.E.2d 859 (1981). If more than a scintilla of evidence as to each element of the offense is presented, then the case must be submitted to the jury. State v. Agnew, 294 N.C. 382, 387, 241 S.E.2d 684, 688 (1978).
A criminal conspiracy is an agreement between two or more persons to do an unlawful act or to do a lawful act in an unlawful way or by unlawful means. To constitute a conspiracy it is not necessary that the parties should have come together and agreed in express terms to unite for a common object; rather, a mutual, implied understanding is sufficient, so far as the combination or conspiracy is concerned, to constitute the offense. The conspiracy is the crime and not its execution.... The existence of a conspiracy may be established by direct or circumstantial evidence. "Direct proof of the charge [conspiracy] is not essential, for such is rarely obtainable. It may be, and generally is, established by a number of indefinite acts, each of which, standing alone, might have little weight, but, taken collectively, they point unerringly to the existence of a conspiracy." [Citations omitted.]
State v. Abernathy, 295 N.C. 147, 164-165, 244 S.E.2d 373, 384 (1978).
A review of the record tends to show that there was ample circumstantial evidence to sustain the charges. Reasonable inferences drawn from the evidence of meetings, personal conversations and the telephone call tend to show that there was a mutual, implied understanding that there would be a sale and delivery of marijuana. This assignment of error is without merit.

II.
Defendant contends that his conviction of conspiracy must be set aside because neither of the two individuals with whom he was alleged to have conspired was convicted of felonious conspiracy charges. Prior to defendant's trial the conspiracy charges against Burcham were dismissed upon a district court finding of no probable cause. After defendant's trial at which Melton testified for the State, the State accepted from Melton a plea of no contest to a misdemeanor charge of maintaining a vehicle for the purpose of sale and delivery of a controlled substance. Defendant maintains that those actions, i.e., dismissal of charges against Burcham and a negotiated plea to a lesser charge by Melton, constitute judgments of acquittal as to both on the charges of conspiracy. We do not agree.
On an indictment for conspiracy in which the co-conspirators are named, if all named co-conspirators but the defendant are acquitted, the conviction of the one may not stand. State v. Raper, 204 N.C. 503, 168 S.E. 831 (1933); State v. Gardner, 84 N.C. 732 (1881); State v. Tom, 13 N.C. 569 (1830). In the absence of acquittals of all named co-conspirators, the defendant's conviction will stand. State v. Davenport, 227 N.C. 475, 42 S.E.2d 686 (1947).
Here, however, there is no evidence that the two named co-conspirators were acquitted. While defendants urge that the dismissal of the charges upon a finding of no probable cause is the equivalent of an acquittal, it clearly is not. In addition, the record makes reference to a plea arrangement between Burcham and *272 the State but contains no evidence of an acquittal of Burcham. The record is not clear as to whether the plea arrangement concerns misconduct pursuant to this conspiracy. Where one defendant charged with conspiracy enters a plea of no contest to a lesser included charge, his co-conspirator may alone be convicted of the conspiracy. State v. Anderson, 208 N.C. 771, 182 S.E. 643 (1935). Further, Melton's plea of no contest to lesser related charges clearly does not serve as a judgment of acquittal to the conspiracy charges. Since there is no evidence that both named co-defendants have been acquitted of the conspiracy charge, defendant's argument must fail.

III.
The last two issues raised relate to the denial of defendant's motion for appropriate relief. They are considered together because the resolution of one issue necessarily resolves the other.
In his motion, defendant contends that he is entitled to relief because the prosecution improperly influenced Burcham so as to cause him to refrain from testifying on defendant's behalf and because the court refused to permit defendant to offer oral testimony in support of his motion for appropriate relief. The basis for this first contention is the allegation that an assistant district attorney contacted Burcham's attorney and told him that the State would not honor a plea arrangement with Burcham if he testified for the defendant. Affidavits from two assistant district attorneys show that neither improperly influenced Burcham or his attorney, but that they merely tried to clarify whether or not Burcham was to testify at trial. Burcham's attorney's response was that his client "knew nothing" about which he could testify. Further, he stated that his client had not been called to testify. Burcham was never subpoenaed by defendant. From these facts the trial court properly concluded that there was no evidence of prosecutorial misconduct and properly denied defendant's motion for appropriate relief.
The trial court is not required to permit oral testimony when considering a motion for appropriate relief if made pursuant to G.S. 15A-1414, when only questions of law arise, or when the court determines from the materials submitted that the motion is without merit. G.S. 15A-1420(c)(1). Here the motion was based on grounds stated in G.S. 15A-1414(b) and acceptance of testimony in addition to affidavits was not required.
In the trial and in denial of the motion for appropriate relief, there was
No error.
HEDRICK and HILL, JJ., concur.
