FENNVILLE, MI — It was 1995 when Sara Porter fell in love with a guy named Harold while she was caring for his ailing mother. Harold "Butch" Knight was much older than Porter, 18 years to be exact, but the gap in age didn’t stop their love from budding and eventually blossoming.

Porter was a successful respiratory nurse therapist who had a natural way with others. Knight, on the other hand, didn't have as much drive and passion to succeed, and some wondered what Porter saw in him.

As for the love she shared in the beginning and throughout her relationship with Knight, Sara's daughter, Roxanne Cameron-Harris, tells In Pursuit, "My mom really, really loved Butch." Cathy Van Horn, Sara's close friend, also remembers the affection the couple shared. She says they were always having picnic lunches, visiting lighthouses in Maine and Michigan, and both had a passion for kayaking.

Although the relationship appeared to be great on the surface, many say Knight treated his wife's daughters badly. Cameron-Harris remembers as a teen that Knight was never supportive and sometimes would speak down to her. She specifically recalls the various personalities Knight displayed: "It was almost like dealing with two different people. Something wasn't right with him." She said he wanted things on the outside to look perfect with his relationship, but “he had this darker, eviler side with me and my sister. When my mom wasn’t around … he would pick fights with us.”

There were also other red flags about Knight. Loved ones say he seldom worked and often relied on Sara to support their family. Knight was also possessive and was generally known to call the shots about everything in their life, from who Sara socialized with to their finances. Despite his downsides, those around Sara supported her marriage because of the fondness she had for him.

But by 2007, just a couple of years after the couple married, their relationship was not in a healthy place, and Sara knew she had to do something drastic to save her marriage. In an effort to try and make things better, she suggested a change of pace. She wanted to move to Maine — and surprisingly Knight was on board.

The pair packed up their belongings, left their family, and headed east. Sara found work as a nurse, and Knight finally got one of the few jobs he had during their relationship, driving box trucks for the hospital.

LEAVING BUTCH KNIGHT BEHIND IN MAINE
After seven years of living on the East Coast, Sara made the call to her daughter that everyone was waiting for. She said she didn't want to live in Maine anymore, and she was packing her things and leaving Knight behind.

When she arrived back in Michigan she moved in with Cameron-Harris and her husband. "Obviously something had happened out there, but she never told us what it was," Cameron-Harris says.

During the time Sara lived with her daughter, little was said about Knight, and he really didn't come up in their conversations. It wasn't until Cameron-Harris came across a letter from Knight to Sara in the back of her Bible that she realized reconciliation was a possibility. A line in the letter read, "I'm doing the list of things you want me to do."

Eventually the couple did get back together. Knight moved back to Michigan as well and found a new home with Sara, but it seems not much changed in their relationship. Knight still wasn't willing to pull his weight and provide for his family. Their new situation left Sara working several hospital jobs and traveling extensively all over the state to make ends meet.

DEADLY CALL TO 911
On January 11, 2015, something snapped inside the couple's home in Fennville, Michigan. Investigators say Butch Knight called 911 dispatch saying, “I strangled her; she’s dead and laying on the living room floor.” The operator asks for the caller’s name, and Knight responded with no emotion, “Uh, that’s not important, I’m getting ready to leave the country…. But we need to get law enforcement there to do whatever they do with dead bodies.” Knight then hung up.

The authorities raced to the home. Detective Craig Gardiner of the Allegan County Sheriff's Office tells In Pursuit, "It was brutally cold that morning ... when we approached, there were no cars or anything in the driveway…. We made entry to see if we could render any aid based on the phone call."

They were able to determine that Sara had been dead for two full days before the call for help was made from a burner phone in Ann Arbor, Michigan. "I've been doing this 24 years, and this is the only case where the person actually confessed to a homicide," Gardiner adds.

The investigation also discovered that Knight had taken out a large sum of money prior to his 911 call, and on January 12, 2015, he closed their bank account. He also purchased a Glock model 22, .40-caliber handgun with 40 rounds of ammunition.

MYSTERY PACKAGE
Two weeks after Sara's murder, a few bizarre updates happened with the case. First, investigators say there were multiple sightings of Knight in the state of Maine where he once lived. Around the same time, Porter's mother, Carolyn Porter, received a delivery. It was a package from Knight. Instead of opening it, she immediately called the police and turned the package postmarked from Maine over to them.

One year after the murder, investigators publicly revealed the contents of the disturbing package. There were letters inside taunting the family. One of the things Knight reportedly said was that he was going to get away with murder because he watches a lot of crime shows. In another note, Knight allegedly revealed a possible motive for the killing: "To do what I had to do to keep ... drug sales incoming." Butch claimed he was dealing drugs and that Porter was a liability. Investigators say they have no evidence of Knight involved in any type of drug sales.

And in an oddly considerate overture, Knight had also put $2,000 in the package to cover the cost of cremating Porter, because Knight claimed that’s what she had wanted.

COPS FIND KNIGHT'S ABANDONED CAR
On January 31, 2015, police in Farmington, Maine, discovered Knight's abandoned 2011 green Subaru Forester in a Walmart parking lot. Surveillance shows Knight at the store, but he’d changed his appearance. His hair and mustache were dyed black, and he was wearing a camouflage snowsuit. It's believed, according to authorities, he hitched a ride to Rangeley, Maine, and it is possible he then crossed the border into Canada.

After the murder, investigators say Knight appeared on their radar two more times. In early February 2015, U.S. Marshals were sent to a motel in Maine. The owner at the motel recognized Knight in a photo and said he’d checked in under a different name only four days after Sara was killed. Knight was believed to be staying at that motel from January 15 to 19, 2015. In May 2015, Sara's family believes Knight used her Facebook account to "like" a family photo.

Once Knight is finally captured, Cameron-Harris wants everyone to know, "I told the police department to bring him in alive, because I want my day in court. I want to see him in orange standing there in front of the judge and be put away."

TRAITS & CHARACTERISTICS:

• Height: 6 feet 5 inches
• Weight: 250-300 pounds
• Eyes: Hazel
• Hair: Balding with white hair. Last seen with hair and mustache dyed black
• Race: White
• Present Age: 70
• Last Seen: Rangeley, ME
• Known to wear glasses
• Diabetic, may be treating his diabetes with holistic remedies
• Known to frequent speciality health stores
• Interested in the Amish lifestyle. Could be hiding out in an Amish community.
• Scar on his abdomen
• Not known to have many friends, introverted
• Used to drive a box truck
• Has training in truck driving, computers, woodworking, and accounting
• Loves to kayak
• His weight may be on the heavier side
• Hard of hearing
• May still be using his wife's Facebook and Instagram accounts

For more on this case, watch the “Tragic Entanglement” episode of In Pursuit With John Walsh on Wednesday, January 16 at 10/9c on Investigation Discovery! Or catch up on ID GO.