Where a challenge to the array is made, the challenger must stand ready to prove his challenge by showing the illegality of the panel. This may be done by oral evidence or by affidavit. The latter is the better practice.15

10 Siebert vs. People, 143 Ill., 578;

Borrilli vs. People, 164 Ill., 557.

11 State vs. Cole, 9 Hump. (Term.), 627; Poindexter vs. Com., 33 Gratt. (Va.), 766; Wilhelm vs. People, 72 Ill., 471. n Hughes' Cr. Law, Sec. 2917;

Gropp vs. People, 67 Ill., 160. 13 Hughes' Cr. Law, Sec. 2916;

Patterson vs. State, 48 N. J., 381 14 Hanna vs. People, 86 Ill., 244.