This is Wisconsin’s first published decision about how parties are to authenticate photographs of text messages so that they are admissible at trial. The answer is the same way they authenticate other kinds of evidence–via §909.01 and §909.015. Nothing more is required.
At Giacomantonio’s trial for sexual exploitation of a child, the State offered, over objection, photographs of the victim’s cell phone screen, which showed text messages between her and Giacomantonio. The detective who took the photographs read them at trial and identified the phone number associated with each message. The victim, her cousin and her mother, all of whom had access to these phones, also testified about them.
Giacomantonio argued that authentication requires more that having a witness identify whose phone the texts were sent from. Someone else could have sent the messages from that phone. Thus, to authenticate a text message courts from other jurisdiction have required the texter’s admission, eyewitness testimony, or clues within the text that reveal the author. See e.g. State v. Francis, 455 S.W.3d 56 (MO. Ct. App. 2014); State v. Michael Koch, 334 P.3d 280 (Idaho 2014); State v. Taylor, 632 S.E.2d 218 (N.C. Ct. App. 2006); State v. Otkovic, 322 P.3d 746, (Utah Ct. App 2014); Rodriguez v. State, 273 P.3d 845 (Nev. 2012). Giacomantonio claimed that the text messages at issue in his case lacked these forms of authentication. The court of appeals disagreed:
¶21 We conclude that the authentication was properly established here through circumstantial evidence. The detective testified that he saw the text messages when the victim’s mother brought the phone to him, that he took the screen shots of the messages, and that the screen shots accurately depicted the text messages he viewed. That testimony, the State argues, and we agree, sufficiently authenticated the screen shots as to their accuracy in representing what the detective saw on the phone.
¶22 Next, the victim testified that Giacomantonio was the author. The victim testified to the phone number that was associated with Giacomantonio’s phone, that she understood the messages had come from him, and that the messages used in the exhibits at trial were typical messages she would receive from him . . .
¶23 Additionally, circumstantial evidence as to the timing of the messages supported a finding that Giacomantonio likely wrote the messages. For example, the first message read “Come to my room” and was sent during the early morning hours of August 7. That language and the timing suggest that someone in the victim’s home wrote it because of the specificity of the location “room.” That writer was likely Giacomantonio, given that the message came from his phone number and that he stayed in a room separate from the victim and from her mother.
¶26 As to the out-of-state authority that Giacomantonio cites, the authentication here was consistent with those courts as well. Giacomantonio himself concedes that courts have determined that text messages do not “warrant different or more stringent authentication rules than those that are used to authenticate other sorts of correspondence.” Collectively, those courts have agreed that text message authentication is a low standard that can be achieved with the sort of testimonial evidence of a witness with knowledge and circumstantial evidence as was presented here. Additionally, those courts have generally agreed that text and other electronic messages do not require new rules on authentication. See, e.g., Thompson, 777 N.W.2d at 625-26 (collecting cases). We agree.