What follows is an opinion from a United States Court of Appeals.
Your task is to identify the issue in the case, that is, the social and/or political context of the litigation in which more purely legal issues are argued. Put somewhat differently, this field identifies the nature of the conflict between the litigants. The focus here is on the subject matter of the controversy rather than its legal basis.
Your task is to determine the specific issue in the case within the broad category of "criminal - federal offense".

Opinion:
UNITED STATES of America, Appellee, v. Clyde Wallace STAMEY, Appellant.
No. 13801.
United States Court of Appeals, Fourth Circuit.
Decided April 1, 1970.
Alton T. Cummings, Asheville, N. C. (court-appointed counsel) for appellant.
Keith S. Snyder, U. S. Atty. for the Western District of N. C., and James O. Israel, Asst. U. S. Atty., for appellee.
Before HAYNSWORTH, Chief Judge, and CRAVEN, and BUTZNER, Circuit Judges.
PER CURIAM:
Clyde Wallace Stamey appeals from a conviction for bank robbery [18 U.S.C. § 2113], assigning as error the admission of police officers’ testimony quoting a prior consistent statement made by a government witness.
The testimony was properly admitted. The declarant was subject to cross-examination concerning the statement, and the testimony of his prior consistent statement was offered to rebut charges of recent fabrication or improper motive. See generally Proposed Rules of Evidence for the United States District Courts and Magistrates, 8-01(c) (2) (ii), and Advisory Committee’s Note (c) (2) (ii), pp. 159 and 165 (Preliminary Draft, 1969).
The judgment is affirmed.

Question: What is the specific issue in the case within the general category of "criminal - federal offense"?

Choices:
murder
rape
arson
aggravated assault
robbery
burglary
auto theft
larceny (over $50)
other violent crimes
narcotics
alcohol related crimes, prohibition
tax fraud
firearm violations
morals charges (e.g., gambling, prostitution, obscenity)
criminal violations of government regulations of business
other white collar crime (involving no force or threat of force; e.g., embezzlement, computer fraud,bribery)
other crimes
federal offense, but specific crime not ascertained

Answer: 4