In the series, Steven Avery's incident with his cat is only brought up briefly, when he is talking about his criminal record. "I really ain't got much on my record. Two burglaries with my friends. We just rode around, get something to do. And we decided to rob a tavern and that was the first time that I got busted with them friends. Another mistake I did I had a bunch of friends over, and we were fooling around with the cat and, I don't know, they were kind of negging it on and I tossed him over the fire and he lit up. You know, it was the family cat. I was young and stupid and hanging around with the wrong people."
PETA has released a statement condemning the series for trying to downplay his crime, which was actually more deliberate and gruesome.
"Too often, cruelty to animals is swept under the rug, as seems to have happened in Making a Murderer when filmmakers omitted specific details about how Avery, at age 20, doused the family cat with lighter fluid before throwing him onto a fire. Avery was convicted of misdemeanor cruelty to animals for killing the cat and served only nine months.
Fortunately, today, the FBI recognizes cruelty to animals as a precursor to further violence and tracks animal abuse like it does homicides, and cruelty to animals is also a felony in most states. The filmmakers were wrong to gloss over this important information, and viewers are rightly upset."