The Federal Courts
have thus far addressed the authentication of computer-generated
evidence based upon the same rules, principles and statutes that
have existed before computer usage became widespread.
The recent case of United States v. Tank, 200 F.3d 627 (9th Cir.
2000), which involves evidence of Internet chat room conversation
logs, is no exception to this trend.
In Tank, the
Defendant appealed from his convictions for conspiring to engage
in the receipt and distribution of sexually explicit images of
children and other offenses. Among the issues addressed on
appeal was whether the government made an adequate foundational
showing of the relevance and the authenticity of a co-conspirator’s
Internet chat room log printouts. A search of a computer
belonging to one of Defendant Tank’s co-conspirators, Riva,
revealed computer text files containing "recorded"
online chat room discussions that took place among members of the
Orchard Club, an Internet chat room group to which Tank and Riva
Riva's computer was programmed to save all of the conversations
among Orchid Club members as text files whenever he was online.
At an evidentiary
hearing, Tank argued that the district court should not admit the
chat room logs into evidence because the government had failed to
establish a sufficient foundation. Tank objected that there
was no foundation for admission of the chat room log printouts
into evidence because: (1) they were not complete documents, and
(2) undetectable "material alterations," such as changes
in either the substance or the names appearing in the chat room
logs, could have been made by Riva prior to the government’s
seizure of his computer.
The district court ruled that Tank's objection went to the
evidentiary weight of the logs rather than to their admissibility,
and allowed the logs into evidence. Tank appealed and the
appellate court addressed the issue of whether the government
established a sufficient foundation for the chat room logs.
The appellate court
considered the issue in the context Federal Rule of Evidence
901(a), which provides that the “requirement of authentication
or identification as a condition precedent to admissibility is
satisfied by evidence sufficient to support a finding that the
matter in question is what its proponent claims.” The
court noted that "’[t]he rule requires only that the court
admit evidence if sufficient proof has been introduced so that a
reasonable juror could find in favor of authenticity or
identification.'" United States v. Black, 767 F.2d
1334, 1342 (9th Cir.1985) . . . The government must also establish
a connection between the proffered evidence and the defendant. See
In authenticating the
chat room text files, the prosecution presented testimony from
Tank’s co-conspirator Riva, who explained how he created the
logs with his computer and stated that the printouts appeared to
be an accurate representation of the chat room conversations among
members of the Orchid Club. The government also established
a connection between Tank and the chat room log printouts. Tank
admitted that he used the screen name "Cessna" when he
participated in one of the conversations recorded in the chat room
log printouts. Additionally, several co‑conspirators
testified that Tank used the chat room screen name
"Cessna" that appeared throughout the printouts.
They further testified that when they arranged a meeting with the
person who used the screen name "Cessna," it was Tank
who showed up.
Based upon these
facts, the court found that the government made an adequate
foundational showing of the authenticity of the chat room log
printouts under Rule 901(a). Specifically, the government
“presented evidence sufficient to allow a reasonable juror to
find that the chat room log printouts were authenticated.”
As to the issue of
completeness, the court determined that any question of the
completeness of the chat room log printouts would have affected
the weight of the evidence, and not their admissibility.
Additionally, the Court discounted Tank’s argument that because
Riva could have made material deletions to the evidence prior to
its seizure by U.S. Customs agents, the Government was required to
establish that no such material deletions occurred.
Interestingly, Tank argued on appeal that the Government was
required to conduct a computer forensic analysis on Riva’s hard
drive to ensure that the files in question were not materially
altered by Riva prior to the seizure. The court found
otherwise, noting that such an exercise was not required by the
Government for authentication purposes, but again, was an issue
relevant to the weight of the evidence.
The Tank decision is
consistent with other cases that have addressed the issue of the
authenticity of computer evidence in the general context of
The Tank case illustrates that there are no specific requirements
or “magic formula” for the authentication of chat room
conversation logs, but that the facts and circumstances of the
creation and recovery of the evidence as applied to Rule 901(a) is
the approach generally favored by the courts.
Authentication of Computer-Generated Evidence In the United States
Federal Courts, (1995) 35 IDEA:J.L.& Tech. 437, 439.
United States v. Tank, supra, 200 F.3d at 629
Id. at 630
Id. at 631
Id. at 631, fn. 5
See also, United States v. Whitaker 127 F.3d 595, 601(7th Cir