Making a Murderer: If Steven Avery Didn't Kill Teresa Halbach, Who Did?

Netflix's much-discussed docuseries Making a Murderermakes a pretty compelling case that Steven Avery may be serving a life sentence for a crime he didn't commit. (If nothing else, the show presents nearly irrefutable evidence that Avery, at a minimum, should not have been found guilty.) But one big question that's left unanswered after the 10 episodes is: If Steven Avery didn't kill photographer Teresa Halbach, who did?

Though Avery's legal team did not present an alternative narrative for who may have committed the crime, some Making a Murderer viewers have done their own detective work and come up with their own ideas, most of which have been thoroughly dissected on Reddit and other websites. (Filmmakers Moira Demos and Laura Ricciardi, as well as Avery's attorney Dean Strang, declined to speak with TVGuide.com for this story.) Here are six other theories about how Teresa Halbach may have died:

Steven Avery finally comments on Making a Murderer

1. Scott Tadych and/or Bobby Dassey killed her.

Steven Avery's nephew Brendan Dassey was also convicted of first-degree murder after (dubiously) confessing to police that he helped his uncle rape and kill Teresa. But there is some evidence to suggest that perhaps Brendan's brother Bobby and stepfather Scott were the real culprits. In fact, Steven himself cast suspicion on Bobby and Scott in a postconviction motion he filed in 2009. Teresa Halbach was coming to the Avery property on October 31, 2005 to photograph a van belonging to Brendan's mother, Barb, and both men (Tadych was dating Barb at the time) were at the house that day. Tadych has a criminal history that includes assault, battery and trespassing charges, and Bobby reportedly had scratches on his neck that he said came from a puppy. In addition, Tadych and Dassey are each other's only alibis - each claims he passed the other one on a road outside the Avery property, and no one else can account for their whereabouts that afternoon. A co-worker of Tadych told police that, after Teresa's murder, Tadych was trying to sell a .22 rifle (the type of weapon believed to have killed Teresa) that he said belonged to one of the Dassey boys. Neither man was fingerprinted and their property was not searched. After Avery was convicted, Tadych told the press: "What happened yesterday is the best thing in the world."

2. The Zipperer family (or someone else outside of the Avery property) had something to do with it.

Who? According to one Reddit user, it's possible that the Avery property wasn't Teresa's last stop on the day she died. The theory, based on Teresa's phone records, goes like this: On the afternoon of October 31, Teresa was on her way to photography jobs at George Zipperer's house and then the Avery salvage yard. At 2:12 p.m., she left a message for Mr. Zipperer saying she is running late and can't find the property. At 2:24 p.m., she gets a voicemail from Steven Avery. Three minutes later, she calls her boss at Auto Trader. Did she decide to skip the Zipperer's house, head straight to the Avery property (which she was familiar with, having been there several times before), and then stop at the Zipperers' on her way home? Bobby Dassey testified that he saw Teresa taking photos on the Avery property around 2:30 p.m., and JoEllen Zipperer testified that Teresa arrived at their property around 3 p.m. or later., but that she never saw Teresa leave the property. When police questioned George Zipperer on Nov. 3 about Teresa's movements that day, he became "extremely belligerent" and, according to Avery's defense team, told "a series of lies about his own activities ... denying that he had contacted Auto Trader or arranged for photographs of the car." He was never investigated as a suspect.

Making a Murderer producers react to criticisms

3. Teresa was killed by her ex-boyfriend, Ryan Hillegas, or someone else close to her.

Making a Murderer viewers may remember Hillegas' eyebrow-raising testimony that he guessed Teresa's password and hacked into her voicemail after her disappearance. Hillegas testified that he listened to some of her phone messages, and evidence shows that some messages were deleted from Teresa's phone in the days after she went missing. Hillegas was never considered a suspect, but he's not the only person close to Teresa who acted strangely after she went missing. Her roommate didn't report her missing for several days, and her brother Mike told reporters before her body was even found that he was "grieving" for his sister.

4. One of Steven's other family members was involved.

In the same court filing in which he implicates Scott Tadych and Bobby Dassey, Avery also says that his own brothers, Charles and Earl, may have had reason to kill her. Charles Avery was previously charged with sexually assaulting his own wife, and Earl had been charged with sexually assaulting his daughters. Customers at Avery Salvage Yard had also previously reported Charles for stalking. Among the trailers on the Avery property, Charles' is the closest to where Teresa's car was found, and he has no alibi for the afternoon of October 31. Earl's alibi is that he and a friend were driving a golf cart around hunting rabbits on the property (a cadaver dog later "alerted," or indicated the presence of human remains, on the golf cart during the police investigation). When authorities came to take a DNA sample from Earl on November 9, 2005, he hid in an upstairs bedroom. As for their motives for framing their own brother, Steven maintains that his brothers were jealous of the large monetary settlement he was set to receive from the county for his wrongful rape conviction, and were also seeking a greater share of the family business.

Steven Avery's ex-fiancee says he's not innocent

5. Teresa was one of serial killer Edward Wayne Edwards' victims.

John Cameron, a former police sergeant and member of the FBI's cold case task force, believes Teresa's murder may have been committed by Edward Wayne Edwards, a serial killer who often framed other people for his crimes. Cameron wrote an entire book on Edwards, who was arrested in Wisconsin in 2009 and later confessed to five murders, though he's suspected of many more. He died of natural causes on death row on April 7, 2011. (Cameron also believes Edwards was responsible for other infamous murders, including JonBenet Ramsey, the West Memphis Three/Robin Hood Hills killings and the Black Dahlia murder). Edwards lived only an hour away from the Avery property during the time of Teresa's murder, and many of his other victims were killed on Halloween. Here's a video outlining the Edwards theory in detail:

6. The entire thing was a frame job by police.

The least credible of the alternative theories. While Making a Murderer is damning to the Manitowoc County Sheriff's Department, and suggests that some investigators may have planted or tampered with evidence, it's a stretch to think that members of the department - no matter how corrupt - would have killed an innocent woman just to get revenge on a troublemaking citizen. Much more plausible? That the department had another suspect or suspects that they neglected to investigate in order to convict Steven Avery.

All 10 episodes of Making a Murderer are available to stream on Netflix. Do you think Steven Avery is guilty? If not, who do you think killed Teresa Halbach? Share your theories in the comments!