Making a Murderer Wikia
Making a Murderer Wikia

The “red fluid” stain is a stain found on the floor of Steven Avery’s garage. It is the result of the spilling of a fluid with a reddish or dark-reddish colour. According to Brendan Dassey the stain appeared sometime in the evening of October 31, 2005, the day Teresa Halbach disappeared. Together with his uncle he attempted to clean the stain with gasoline, paint thinner and bleach. In some interviews Brendan said it was a red fluid from a car, possibly transmission fluid, that leaked on the floor from underneath the car after Steven had just poked somewhere under the car. In other interviews he would say it was blood.

The stain was initially difficult to see with the naked eye. Luminol, a fluorescent substance, was needed to make the stain more visible.


A 4'x3' smear that was almost invisible to the naked eye. It was slightly different in colour from the surrounding concrete. The stain was right behind a green lawnmower. When luminol was applied to the stain it gave a faint bluish glow.


On Tusday 8 November 2005 the Wisconsin State Crime Lab entered the garage and chalked areas of interest and put some luminol, a substance which emits a bluish glow when it comes in contact with blood, on some of those areas. After this had been done all doors and windows were closed and lights were turned off to make the garage completely dark. Behind a green lawnmower a 4'x3' spot emitted a faint bluish glow. John Ertl of the Crime Lab chalked this area.[2]

In May 2006 Brendan Dassey made several drawings of the crime scenes, including one of the garage. He drew an almost empty garage, with only a snow mobile and a lawnmower inside it. Right behind the lawnmower he drew the victim lying on the floor and between the lawnmower and the victim he drew her blood. The exact same location where the luminol had lit up. Brendan described the blood as 4'x3' in size.

At trial Brendan explained that on the night of Halloween, several hours after the victim was on the property, he and his uncle cleaned one spill in the garage, while they were having a bonfire outside. The spill was cleaned with gasoline, paint thinner and bleach.

Forensic examination[]

The stain had been submitted to a luminol test. Luminol is a fluorescent substance that will give a bluish glow when it comes in contact with certain substances or materials, such as blood, but also to other things, such as bleach and oil.[3] When the luminol was applied the stain gave a faint bluish glow.[4] Parts of the stain were swabbed and the swabs were tested with phenolphthalein,[4] which is a test that, unlike luminol, can test more specific on the presence of blood, but is less sensitive than luminol. The phenolphthalein-test did not react to the presence of blood.[4]

At trial and appeals[]

At Steven's trial the stain was brought up during Forensic Scientist John Ertl's testimony.[5] He explained how the smear lit up with luminol but did not react to phenolphthalein. When prosecutor Tom Fallon asked him what that meant to him Ertl explained that he doesn't know what it was that reacted to the luminol. He explained cleaning chemicals can cause a reaction, but also added that blood can be diluted and avoid being detected by phenolphthalein if diluted enough.[4] Thus, there was nothing for them to collect here.

Defense attorney Buting asked Ertl if luminol reacts very brightly to bleach, and Ertl answers it does. Buting then asks if luminol reacts to transmission fluid, but Ertl is unsure if it does.[3] Buting points out Ertl earlier said the luminol gave a faint glow when it was applied to the red fluid stain and not a bright quick one which you would expect from bleach. Ertl agreed.[6] Bringing up phenolphthalein again, Buting asks if it detects both human and animal blood, to which Ertl agrees, and whether it found any in the red fluid stain. Ertl said it didn't.[6]

In return, Fallon asks Ertl if bleach is effective in dealing with blood. Ertl responds it's very effective and very useful for that as it destroys the blood and the DNA. It decontaminates it. Ertl states the State Crime Lab personnel uses it to clean the work areas.[7] Fallon then asked Ertl if he thinks it's possible to clean a pool of blood from a garage floor beyond detection of a phenolphthalein-test, and Ertl answers its possible and bleach would be a good thing to use.[7]

During Sherry Culhane's testimony Buting puts up a photo of Steven's garage and asks if you would clean the garage floor with bleach you wouldn't find any DNA on the floor. Culhane agrees that's true if it was cleaned thoroughly enough.[8]

At Brendan Dassey's trial similar questions were asked, again to Ertl, about the red fluid stain. Attorney Fremgen asked if luminol was applied to the entire garage floor and Ertl answered it was not.[9]

2016 - 2021 Kathleen Zellner appeals[]

Zellner has not commented on the red fluid stain in any of her filings. Zellner had Avery sign three affidavits in which he details his activities on the 31st of October 2005, but he makes no mention of cleaning the garage with Brendan in any of those.


See also[]


  1. Dassey Trial Transcripts, day 2 - testimony of John Ertl, page 159
  2. Dassey Trial Transcripts, day 2 - testimony of John Ertl, page 166
  3. 3.0 3.1 Avery Trial Transcripts, day 6 - testimony of John Ertl, page 120
  4. 4.0 4.1 4.2 4.3 Avery Trial Transcripts, day 6 - testimony of John Ertl, page 60
  5. Avery Trial Transcripts, day 6 - testimony of John Ertl, page 59
  6. 6.0 6.1 Avery Trial Transcripts, day 6 - testimony of John Ertl, page 121
  7. 7.0 7.1 Avery Trial Transcripts, day 6 - testimony of John Ertl, page 136
  8. Avery Trial Transcripts, day 11 - testimony of Sherry Culhane, page 113
  9. Dassey Trial Transcripts, day 2 - testimony of John Ertl, page 179