Convicted of the offense of possessing deadly weapons while in custody in a penal institution, Johnny Harper files this pro se appeal, and we affirm.

1. A tower guard saw an inmate in the yard pass something to another inmate who was wearing a yellow shirt. Upon receiving this report, Lt. Harry Wingate, a correctional officer, approached Harper, who was wearing a yellow shirt and seated on a trash can, and told him to stand up. Underneath Harper was a white shirt bearing his prison number in which were wrapped two prison-made knives. Harper worked in the metal fabrication shop and the knives were made from materials that could be obtained there. The jury was amply authorized to find that the knives were deadly weapons which were in Harper’s possession.

2. The trial judge in reading the indictment to the jury did not change the charge from possession to constructive possession of deadly weapons — he merely explained to the jury that possession could be either actual or constructive and defined each term. This was appropriate and was not in error.

3. Exhibits 1 and 2, the two knives, were properly identified and introduced in evidence. Fingerprint identification is not a requirement for evidence to be admissible.

4. Lt. Wingate’s testimony was credible enough for the jury to find Harper guilty, and was legally sufficient to *147support their determination construed as we must in the light most favorable to the prevailing party, in this case the state. Alexander v. State, 138 Ga. App. 618 (1) (226 SE2d 807) (1976).

Judgment affirmed.