|Division|| Queens Homicide Squad (2003-present)|
Manhattan Special Victims Unit (2003; temporarily)
|Precinct|| 48th Precinct (1998-2003)|
16th Precinct (temporarily)
Detective Dave Duethorn is a rookie gold shield detective.
Dave grew up next to the first Deputy Commissioner and eventually joined the NYPD with him as his rabbi. After five years patrolling the 48th Precinct, his neighbor got him a promotion to detective, and he was subsequently transferred to Queens Homicide.
Dave was called to the video store shooting and interviews the clerk who shot the shooter, Joey Field. After Joey displays some initial shock, he instructs the paramedics to take him home. When one of the shooting victims, Rebecca Kurtz, tests positive for gonorrhea, he calls the Special Victims Unit, and they send Detectives Benson and Stabler. In the hospital, he briefs them on the shooting and that Rebecca is likely to die of her injuries. They ask if anyone told the parents about the gonorrhea, and Dave informs them he left that for the experts before leaving.
He is later called in by the SVU after it is determined that the shooting was a setup and both Rebecca and the shooter, Eric Campbell, were killed to cover up the rape. When they pull Eric's rap sheet, Dave speculates that Eric was hired by Joey to kill Rebecca. Captain Cragen asks what Dave's boss wants to do with this, and Dave tells him his lieutenant will follow the SVU's lead on this. Dave gives them Eric's father's address, and Detectives Fin and Munch question him. When Joey is arrested, his father calls Dave in as a witness for the defense to target because there is no corroboration for Rebecca's sister Missy's eyewitness account. Later, the case is resolved when both Missy and Joey are found guilty and Missy is revealed to have orchestrated the shooting. (SVU: "Damaged")
He later calls Fin and Stabler to help investigate a quadruple rape-homicide where a couple and two of their friends were targeted. Dave theorizes that this was a home invasion where they rape and kill them and rob them afterwards. He is shocked when M.E. Warner informs them that the men were raped as well. At the morgue, Dave and Fin learn the men were forced to rape the women and then each other. After discussing what set him off with Huang, Cragen informs Dave that he is temporally assigned to the SVU. Dave approves and later points out there was an extra guest. Dave and Fin interview the father of one of the victims and he gives them a name, Paul Dumont, as they go over what was stolen. They go to Paul's work address to find him, but his boss tells them he is in the hospital. At the hospital, his attending physician tells the detectives he was hit three times in the head with a blunt object.
Dave theorizes with Fin and Munch that Dumont was attacked first and the perpetrator took the flowers he was carrying to gain entry into the townhouse, while Dumont walked a little further before falling. He later visits the crime scene of two new victims, notices the car keys are missing, and says they have a spree killer. They confirm the M.O. is the same for the victims and that they beat victims when they don't cooperate. David later determines the photos were taken as trophies and goes back to the crime seen with Munch. He determines the perpetrator is using a car, and after killing the sixth and seventh victims, he went back for it. Dave and Fin canvass the building but come up empty. As they leave, a witness tells them about the attack and gives them details on the car and a partial plate. Dave takes her back to the precinct to better describe it. They eventually tie the car to Charlie Baker and his brother Billy before they are called to another scene with two male victims. They notify the father of one of the victims, where they realize both men were with dates, who are now missing.
Fin and Dave visit the crime lab, and they give the technicians the killer's approximate weight and the type of shoe he is wearing. They later learn another car the perpetrator was using turned up with someone sleeping inside. They later canvass department stores when the evidence points to a connection and learn Billy works in one. They decide to follow him so he will lead them to the girls. When Billy is caught with credit cards stolen from the victims, he tries to run, but Dave cuts him off. Billy is arrested after Dave pulls a gun on him to unsuccessfully get him to reveal where the girls are.
They search Billy's house and find all of the stolen stuff, after which Dave and Fin interrogate him. They try to get him to tell them where the women are, but Billy asks to see Charlie instead. Dave advises that following his demands is their best shot, but when Billy doesn't confess and two more bodies show up, Fin and Dave go to the scene. Dave determines there are two perpetrators judging from the footprints, which do not match the ones found at earlier crime scenes, and suspicion turns to Charlie. They later find out from Billy's girlfriend that Charlie was raping Billy and threatened to kill both of them if they said anything about it. They convince Charlie and Billy's father to give up Charlie, and he is arrested with the gun he used to kill the couples. They then manage to turn Billy on his brother by revealing where they found the stolen items. As a result, Billy gives them the location while Charlie screams in protest. They recover the women in time, and they are taken to the hospital. (SVU: "Dominance")