
235 A.2d 322 (1967)
Milbourne E. LORD, Jr., Appellant,
v.
DISTRICT OF COLUMBIA, Appellee.
No. 4297.
District of Columbia Court of Appeals.
Argued September 6, 1967.
Decided November 27, 1967.
John A. Kendrick, Washington, D. C., for appellant.
Richard W. Barton, Asst. Corp. Counsel, with whom Charles T. Duncan, Corp. Counsel, Hubert B. Pair and John R. Hess, Asst. Corp. Counsel, were on the brief, for appellee.
Before HOOD, Chief Judge, and MYERS and KELLY, Associate Judges.
MYERS, Associate Judge:
Appellant, together with a co-defendant who is not a party to this appeal, pleaded guilty to publicly committing a lewd, obscene and indecent act in the District of Columbia in violation of 22 D.C.Code § 1112(a) (1961 ed.) and paid an imposed fine. Three months later, through his present attorney, appellant moved to vacate the judgment upon the guilty plea and to have a trial on the merits, apparently upon the theory that, because the court appointed the same counsel to represent both defendants, *323 manifest injustice occurred which was subject to correction under Criminal Rule 20(d) of the trial court. From denial of this motion, this appeal followed.
Because it appears that appellant is employed in a position of trust which may be jeopardized by his conviction, we pass the Government's contention that, by payment of the fine, appellant's appeal was rendered moot and address ourselves to appellant's charge of error.
Whether an attorney for co-defendants is retained or court appointed, the trial judge has the responsibility to inquire if counsel has evaluated the potential conflicts involved in such joint representation and has apprised his clients of any risks. The trial judge must make an affirmative, on-the-record determination that the several defendants are aware of the probable dangers and have intelligently elected to assume the risks of joint representation. Campbell v. United States, 122 U.S.App. D.C. 143, 144, 352 F.2d 359, 360 (1965). In the instant case, we do not know if the trial judge ever addressed himself to this question. Where the record does not show that counsel has made an appraisal and has advised co-defendants of the risks of joint representation, we will not assume that a defendant has waived his right to demand separate counsel. However, a silent record standing alone is not reason enough to reverse an otherwise valid conviction. It must also be shown that the defense was hampered by the joint representation. The precise degree of prejudice need not be measured. Glasser v. United States, 315 U.S. 60, 76, 62 S.Ct. 457, 86 L.Ed. 680 (1942). But "some prejudice, some conflict of interest, resulting from the joint representation must exist before one can be said to have been denied effective assistance of counsel." Lollar v. United States, D.C. Cir., 376 F.2d 243, 246 (1967).[1]
Assessing the record in the light of these criteria, we are convinced beyond a reasonable doubt[2] that it discloses no hint of prejudice to appellant arising out of the joint representation. There was nothing to prevent the attorney assigned to represent appellant and his co-defendant from requesting separate trials under Criminal Rule 7(e) of the trial court. No showing was made that the attorney was forced to advise both defendants to follow the same course. He could have counseled one to plead guilty and the other to plead not guilty; and it does not appear that, even if they had proceeded to trial together, they would have urged conflicting defenses. The prior record of appellant's co-defendant may well have been inadmissible even for impeachment purposes under the Luck Doctrine.[3] Appellant was fully informed of the nature of the charge against him, and at no time has he alleged his innocence. Clearly he has not made a showing of "manifest injustice." Other contentions of error are without merit.
We rule that the trial judge's denial of appellant's motion to vacate the judgment of conviction was proper and not an abuse of discretion.
Affirmed.
NOTES
[1]  See also Ford v. United States, D.C. Cir., 379 F.2d 123 (1967), where the court refused to accept the argument that a showing of prejudice ought to be irrelevant in joint representation cases.
[2]  Lollar v. United States, D.C.Cir., 376 F. 2d 243, 247 (1967); Chapman v. State of California, 386 U.S. 18, 24, 87 S.Ct. 824, 17 L.Ed.2d 705 (1967).
[3]  Luck v. United States, 121 U.S.App.D.C. 151, 348 F.2d 763 (1965). See also Gordon v. United States, D.C.Cir., 383 F. 2d 936 (decided September 18, 1967).
