What is the test for disqualification of an attorney who has been involved in a criminal case?

In United States v. Locascio, 6 F.3d 924 (1993), at p. 933, in upholding a disqualification order, Altimari J. stated: Even if the attorney is not called, however, he can still be disqualified, since his performance as an advocate can be impaired by his relationship to the events in question. For example, the attorney may be constrained from making certain arguments on behalf of his client because of his own involvement, or may be tempted to minimize his own conduct at the expense of his client. Moreover, his role as advocate may give his client an unfair advantage, because the attorney can subtly impart to the jury his first-hand knowledge of the events without having to swear an oath or be subject to cross examination. Those observations were adopted in Bogiatzis. Like Nordheimer J., I, too, concur with the remarks of Mr. Justice Altimari.