Professor's brutal murder uncovers fake identity amid decade-long manhunt

For years, Sue Marcum was a devoted accounting professor at American University in Washington, D.C., living an active and joyful life in suburban Maryland.

Marcum was an avid traveler, dedicated a lot of time to community service work and volunteerism, loved colorful fashion and was a dedicated practitioner of yoga and learning Spanish.

But on Oct. 25, 2010, everything would change when Marcum was found dead in her Bethesda home -- a shocking murder that would bring to light a fake identity and a killer who would vanish for over a decade. 

A new "20/20" episode, "The Hunt for Mr. Right" airing Friday, Jan. 16, at 9:00 p.m. ET on ABC and streaming the next day on Disney+ and Hulu, examines the case.

You can also get more behind-the-scenes of each week's episode by listening to "20/20: The After Show" weekly series right on your 20/20 podcast feed on Mondays, hosted by "20/20" co-anchor Deborah Roberts.

Upon receiving a call from a friend who discovered Marcum deceased in her home, investigators rushed to the house. There, they found Marcum's body at the bottom of the basement steps with a broken bottle underneath her.

"It was a brutal, brutal murder," Washington Post reporter Dan Morse, who covered the story, told "20/20."

Police searched the house and found rooms ransacked, a screen cut in the back of the house and Marcum's Jeep missing.

In Marcum's office, investigators found a life insurance policy with the beneficiary listed as Jorge Rueda Landeros. It was a reciprocal exchange -- Landeros' life insurance policy had Marcum listed as the beneficiary, investigators said.

Authorities began investigating Landeros, discovering that he was a Spanish language and yoga teacher whom Marcum had initially met in 2005 in D.C. He was born in Mexico before becoming a dual citizen in the U.S., according to authorities.

Police also discovered that Marcum and Landeros had been involved in a romantic relationship that had ended. Investigators learned that Marcum gave Landeros a considerable amount of money to invest.

John McCarthy, one of the prosecutors in the murder case, told "20/20" that Landeros had lost over $300,000 of Marcum's money without making any back.

"She was increasingly desperate for money. She had remortgaged her houses. She had borrowed money from her father. She had took money out of her retirement fund," McCarthy said. "She couldn't pay her bills."

Seeking to determine if DNA found at the crime scene matched to Landeros, investigators got a voluntary DNA sample from him while he was living in Juarez, Mexico, and he crossed the border into the U.S. But when the DNA sample Landeros provided to police matched DNA found at the crime scene, he was nowhere to be found, according to investigators.

In 2021, 11 years after Marcum's murder, investigators who began looking into Landeros' social media trail discovered a mysterious individual named Leon Ferrara living in Guadalajara, who was reportedly linked to Landeros.

Police soon made a critical discovery -- Ferrara was Landeros himself, living under an alias.

On the afternoon of December 13, 2022, Mexican agents arrested Landeros while he was walking his dogs and extradited him back to Maryland. He was charged with first and second-degree murder in Marcum's killing but never faced charges for allegedly mismanaging Marcum's money.

At the trial, Landeros pleaded not guilty, as his defense attempted to argue that there were flaws in the case. The defense insisted Marcum's murder was a burglary gone wrong and Landeros was innocent.

Ultimately, the jury found him not guilty of first-degree murder, but guilty of second-degree murder.

Landeros now faces a maximum of 30 years in prison, and he will be sentenced Feb. 6.

Don Williamson, Marcum's friend and colleague, told "20/20" that Marcum was an exceptional individual.

"The warmest, kindest, most wonderful giving person I've ever met in my life. There's just no question about that," Williamson said.

"I think she was always looking in life for love, and she wanted to give love and receive love. And I think that created a personality that was very giving. And that's why she was such a good teacher," he added.