Steven Avery addresses Judge Patrick L. Willis during his sentencing June 1, 2007. Credit: Dan Powers / Appleton Post-Crescent

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About halfway into watching and live tweeting "Making a Murderer," I worried whether we who covered the Steven Avery trial in 2007 had missed something big.

The binge-watchable Netflix series (Is it all people are talking about on social media?) documents, dramatically, the theory that sheriff's deputies in Manitowoc County framed Avery in the murder of Teresa Halbach.

But was what Avery's lawyers presented in his trial as frame-up evidence — when weighed against the DNA-laden evidence against Avery — enough to create reasonable doubt?

It's clear from Internet reaction to "Making A Murderer" that perhaps millions, including hundreds of thousands who signed pardon petitions, disagree with the Avery jury's guilty verdict. There was no such outcry in 2007.

Personally, "Making A Murderer" left me regretting that I did not cover the later trial of Avery's then-teenage nephew, Brendan Dassey, who was also convicted of the Halbach murder. The New York filmmakers, Laura Ricciardi and Moira Demos, raise disturbing questions about Dassey's first lawyer and about confessions made by the learning-disabled Dassey.

Not having covered the Dassey trial, I can't make a judgment about how "Making A Murderer" treats that case.

But after two days and nights immersed in the series, I found my worries about missing something big in Avery's trial had greatly diminished.

My aim is to review key parts of his case — as they were presented in "Making A Murderer" and at his trial.

First, some general observations:

■Those who watched all of "Making A Murderer" saw some 10 hours of film. The jurors (who were from Manitowoc County, even though the trial was held in neighboring Calumet County) heard more than a month's worth of testimony.

■The filmmakers, based on my observations of their work before and during Avery's trial, were talented and tireless — and essentially embedded with Avery's family and his lawyers. That doesn't negate the questions their film raises. But their approach must be considered in evaluating the series.

■"Making A Murderer" focuses compellingly on the Manitowoc County Sheriff's Department, which was largely responsible for Avery's wrongful conviction in a 1985 sexual assault that put him behind bars for 18 years. How, the film asks, could Manitowoc County deputies play a major role in the Halbach murder investigation? After all, at the time, Avery was suing Manitowoc County, seeking $36 million for his imprisonment. And responsibility for the murder investigation had been transferred to the sheriff in Calumet County to avoid any conflict of interest.

■Two of Wisconsin's top lawyers represented Avery, whose case was helped by a $400,000 settlement he received for the wrongful conviction lawsuit. That isn't to say they could not have missed crucial evidence. But these were veteran, resourceful attorneys, not inexperienced and overburdened public defenders.

■The theories of the prosecution and of Avery's attorneys are not necessarily mutually exclusive. Maybe Avery killed Halbach and deputies planted some of the evidence.

It's worth noting that my history covering the 53-year-old Avery, who is serving a no-parole-possible life sentence, is long. I broke the story in 2003 on how new DNA testing would exonerate him of the sexual assault. I was there when Avery emerged from the prison gates. I sat across a table from him for a couple of interviews. And I was on the other end of the phone when Avery said as he was about to be arrested in Halbach's murder: "I'm going to jail. I can't talk to you no more."

Then for nearly two years I covered Halbach's disappearance, Avery's pretrial hearings, jury selection and the five-week trial itself. The details were grisly. Halbach, a 25-year-old freelance photographer who lived in Calumet County, was last seen on the afternoon of Oct. 31, 2005 — by Avery, at his home. She had gone to Avery's trailer, on his family's property in Manitowoc County, at his request to take a picture of a vehicle for sale. Some of Halbach's remains — identified by DNA testing — were found in a burn pit and a burn barrel outside Avery's trailer.

The framing theory centers on two Manitowoc County sheriff's investigators — then-Lt. James Lenk (now retired) and then-Sgt. Andrew Colborn — both of whom participated in the murder investigation.

Now to the evidence.

Question: Did Avery target Halbach?

Kenneth Kratz, who was the Calumet County district attorney at the time, prosecuted Avery and Dassey. (He resigned in 2010 after an unrelated sexting scandal.)

Kratz has said that "Making A Murderer" doesn't mention that Halbach, who did photography for Auto Trader magazine, had been to Avery's home before to take pictures for the magazine. On the day she disappeared, Avery had called the magazine requesting specifically that Halbach come to his house to take a picture of a van he was selling. In addition, Avery had called Halbach's cellphone three times that day, including twice using a feature on the phone that blocked his number, Kratz recalled.

Episode 7 shows testimony from Colborn, the Manitowoc County sergeant, about his questioning of Avery at Avery's home. Colborn said Avery told him that Avery's sister was selling the van that Halbach came to photograph, and that he saw Halbach that day but didn't talk with her.

We reported that when Avery called Auto Trader, he said the van was being sold by the sister, Barb Janda, who lived next door. He identified himself to the magazine as "B. Janda" and gave Janda's phone number.

In addition, we reported that an Auto Trader receptionist said Avery once answered his door wearing only a towel when Halbach came to his home to photograph a vehicle he was selling through the magazine, though the jury did not hear that testimony.

Bottom line: Avery called Halbach to his home, concealing his identity to some extent, and was the last-known person to see her alive after she arrived.

Question:Did Lenk plant Avery's blood in Halbach's car?

A cousin of Halbach's found Halbach's partially hidden Toyota RAV4 on the Avery family property five days after she was last seen. The property is best known for the family's sprawling auto salvage business.

Episode 4 addresses the car by showing attorneys from both sides examining a vial of blood that had a syringe-sized hole on one end. One of Avery's lawyers, Jerome Buting, says an officer must have put blood from the vial in Halbach's RAV4.

The film also shows Lenk, the Manitowoc County lieutenant, testifying that he arrived at the Avery property five hours earlier than what he had said at a pretrial hearing. And a clip shows Buting saying Lenk, in 2001, had signed a form in Avery's sexual assault case that noted there was a vial of Avery's blood kept in the Manitowoc County Courthouse.

So, there were questions about how long Lenk might have had access to Halbach's car, as well as a suggestion that he would have known how to get Avery's blood from the vial.

The film also shows, however, the DNA expert from the FBI testifying about so-called EDTA testing the FBI did on blood smears from inside Halbach's car. The testing, according to the expert, showed the blood almost certainly would have come from Avery bleeding, not from the vial.

Avery's DNA, not from blood, was also found on the hood latch of the car.

Bottom line: Avery's DNA was in and on the murder victim's car, with an allegation, refuted by a DNA expert from the FBI, that Avery's blood inside the car was planted.

Question: How did Halbach's car key get in Avery's trailer?

Episode 3 tells how it was Lenk, the Manitowoc County lieutenant, who found the key to Halbach's RAV4 in Avery's trailer. Buting, who assisted Madison attorney Dean Strang in defending Avery, declares the key was planted. In the next episode, Buting says the key had been found on investigators' seventh entry into Avery's trailer — suggesting there were plenty of opportunities to plant the key.

We reported how Colborn, the Manitowoc County sergeant, testified about how the key was found, three days after Halbach's RAV4 was found. He recalled shaking a bookcase in Avery's bedroom, then Lenk entered the bedroom and said something like, "Ah, there's a key on the floor here." Lenk said it was at least his third time searching the bedroom.

Bottom line: A Manitowoc County investigator finding the key stirs suspicion about whether the key was planted. But the State Crime Laboratory found Avery's DNA on it. So, both the DNA and the key would have had to have been planted to fit the framing theory.

Question: Does a mistake mean contamination?

Episode 6 shows testimony from an anthropologist and State Crime Lab experts saying Halbach had been shot twice in the head — and that a bullet fragment with Halbach's DNA had been found in Avery's garage.

Attorney Buting repeatedly says testing was "contaminated" because the crime lab expert inadvertently got some of her own DNA into the sample.

That expert testified that her DNA did not affect the finding of Halbach's DNA on the bullet.

And we reported that another crime lab expert testified the bullet likely had been fired from a .22-caliber rifle found in Avery's bedroom.

Bottom line:That the tester's DNA was inadvertently introduced into testing doesn't change the fact that Halbach's DNA was found on the bullet fragment found in Avery's garage.

Question: Were Halbach's remains burned where they were found?

Episode 6 shows testimony from the anthropologist, who said bones found in a burn pit and a burn barrel outside Avery's trailer were those of a woman under 35 who had suffered two gunshot wounds to the head. She says it was highly unlikely that the majority of the burning had been done anywhere else.

Avery's attorneys contend that someone other than Avery burned Halbach's body, somewhere else, and then the remains were brought to Avery's property in support of the frame-up.

We noted in our reporting that a forensic dentist identified teeth fragments from Avery's burning pit as Halbach's.

Bottom line: Halbach's incinerated remains were found outside Avery's trailer, with no evidence that they had been burned elsewhere.

My take:"Making A Murderer" raises some valid points, particularly questions on why Manitowoc County deputies participated in the Halbach murder investigation. But those questions don't outweigh the DNA evidence that helped lead a jury to convict Avery.