Keogh (defendant), a dealer at a casino, was charged with underreporting his tips to the IRS from 1969 to 1971. At trial, the tax court found that dealers at Keogh’s casino pooled and evenly split their tips. To prove how much Keogh earned in tips, the Commissioner of Internal Revenue introduced a diary kept by John Whitlock, Jr., another worker at the casino. The diary contained a detailed summary of Whitlock’s tips for the years in question, including dates and total amount of tips received on those dates. Keogh objected to the introduction of the diary on the grounds of hearsay because Whitlock was not available to testify at the trial. The tax court admitted the diary under the record of regularly conducted business activity exception to the hearsay rule. Barbara Mikle, Whitlock’s ex-wife, testified to the regularity, detail, and accuracy of Whitlock’s diary. The tax court found Keogh guilty. He appealed.