|“||The lab's off-site. Come on.||”|
— Erickson tells Hoffman to accompany him and Perez[src]
Layout and Structure
The Wave Audio Forensics Lab was a technical lab used to assist law enforcement authorities by analyzing various kinds of audio sources, which served as evidence in criminal cases. It was a big room located on the basement of a building, which housed numerous complex technical instruments. Despite the lab's importance for the work of the prosecuting authorities, it was located in an external location independent from the authorities' headquarters. (Saw VI)
The Jigsaw Case
At one point the lab played an important role in the investigation of the case of serial killer John Kramer, better known as the Jigsaw Killer. When the murders were continued after John Kramer's death, some suspicious circumstances led the special agents Dan Erickson and Lindsey Perez to reopen the case of Seth Baxter, one of the first victims of the murder series. Thereby, they mainly concentrated on a video tape found at the crime scene. Once they found out that the voice on the tape wasn't that of John Kramer, they tasked Sachi, a technician working at the lab, with the analysis of the tape so she could restore the original voice. (Saw VI)
Even though the voice had been distorted with highly complex audio filtration equipment, Sachi made good progress and called the agents later that day. They arrived at her audio lab shortly afterwards along with Detective Mark Hoffman, whose sister, Angelina Acomb, was the ex-girlfriend of Seth Baxter and had been murdered by him during a domestic dispute. When they came in, Sachi was still working on the tape. As they had to wait some more time, Hoffman took a cup of coffee from the machine in the room. Noticing Hoffman's increasing nervousness, Perez tried to put him under pressure and began to discuss the motivation of Special Agent Peter Strahm for helping Jigsaw, as he had been their key suspect up to this point as his fingerprints had been found at the latest crime scene. Thereby, she stated that she had never suspected Strahm to be mentally unstable during the five years she had worked with him. Erickson then talked about the possibility that Strahm had killed Seth Baxter to throw suspicion on Hoffman. However there was still some detail that didn't fit the picture and therefore he finally revealed to Hoffman, that Strahm, judging by the analysis of his fingerprints, must have already been dead by the time he left his prints at the crime scene.
Seconds later, Sachi restored the tape, finally revealing the voice to be that of Mark Hoffman. However, before the agents could react, Hoffman quickly pulled out a knife from his pocket, slashed Erickson's jugular vein and threw his coffee in Perez's face. Then, he cut off the power and grabbed Sachi, who was shot in the back three times by Agent Perez as Hoffman used her as a human shield. Upon doing so, Hoffman was able to approach Perez and stabbed her multiple times in the abdomen with his knife. He then asked her who else knew about him, to which she responded with her dying breath that everyone knew about him. Calling it a lie, Hoffman stabbed her one final time, killing her in the process. Following the massacre, Hoffman threw away his knife and ran out of the lab. Seconds later, he returned with the severed hand of Strahm, which he had kept in a cooling box in his car trunk, and a gas canister. He placed Strahm's fingerprints all around the room and also on Perez' gun as well as the screwdriver which he had used to cut off the power. Afterwards, he poured the gasoline all over the floor, the corpses and the technical instruments. When he approached Erickson, he briefly hesitated and smiled when he saw that the latter was still alive, before he poured the fuel over him as well. Then, Hoffman set the lab on fire before finally fleeing the scene. (Saw VI)