Sergeant David Gallagher is a police sergeant from the San Francisco Police Department. Sergeant Gallagher was investigating Shady Palms Clinic when rats were coming out dragging pieces of human flesh with them in the process.
After the incident, Sergeant Gallagher became one of Agent Cummings' victims in his killing spree during a massacre over summer.
Sergeant Gallagher is well-dedicated police sergeant. David wants the ensure the well-being and safety of the citizens, however, he wants to ensure that social services takes care of any vagrants, as John Sawyer was being pressured by him to handle Brownie.
Sergeant Gallagher follows the law as Charity wanted him to investigate the Shady Palms Clinic to which her twin sister was going there but never responded back, he did promise that if she didn't respond within a few days, he will set up a search warrant. The warrant came today as Sgt. Gallagher found something wrong as rats came from the basement carrying pieces of human flesh.
Sergeant Gallagher is a middle-aged man.
He has gray hair and a moustache, and has brown eyes.
Hearing a knock on the door, Sgt. Gallagher saw Detective Rothman through door's eye slot. As David begins to unlock it, Agent Cummings quickly tosses her corpse on the floor. As David opens it, Stewart comes around and quickly drives a knife into his throat, placing his free hand on his neck as his pushes him against a pair of filing cabinets.
Struggling to break away, Stewart grabs his gun in the process and pulls out his knife as Sgt. Gallagher drops to the floor.
- Sergeant David Gallagher was investigating Shady Palms Clinic when rats came out of the basement dragging pieces of human flesh.
- Lieutenant Cal Bedowski was killed to keep quiet when he found bodies in the basement of Shady Palms Clinic. Sergeant David Gallagher was killed to get to Jan Beck and being stabbed in the throat symbolizes him being silenced.
- Sergeant David Gallagher died the same way a police officer died in Saw 3D.