The man held in the slaying of a University of Kansas law student and social activist has killed himself while in custody in New Jersey.

Lawrence police said Adolfo Garcia-Nunez, 46, had been arrested Friday evening and was being held in Elizabeth, N.J. The arrest occurred less than 24 hours after Jana Mackey's body was found in Garcia-Nunez's home in Lawrence.

His death caps an unusual relationship between a Cuban émigré artist, who served prison time for assaulting a former girlfriend in 2004, and a 25-year-old student from Hays, Kan., who was passionate about social justice causes, including domestic violence.

"I couldn't figure it out," said Christie Brungardt, Mackey's mother. "He was too old for her.

"She was all about public advocacy, particularly women's rights. She volunteered for anything that would impact the world in a more positive way."

New Jersey officials could not be reached Saturday. Lawrence police have declined to discuss how Mackey was killed or how Garcia-Nunez committed suicide.

Friends and associates described Mackey as a vivacious woman, mature for her years, who was engaged in many progressive causes. She received her undergraduate degree in women's studies from the University of Kansas in 2007 and was a second-year student at the KU School of Law.

"She was one of those people you look forward to talking to," said Elizabeth Cateforis, a KU law professor who is teaching a class in which Mackey was enrolled this summer.

"It was clear she was concerned about violence against women and she had worked as a rape counselor. It seemed to lean her toward being interested in becoming a prosecutor."

Garcia-Nunez came to the United States from Cuba in 1995, according to information posted on his MySpace Web site. His entry said he was born in Havana in 1971, but police records indicate it was 1961. The Web site stated Garcia-Nunez worked in Miami and Kansas City before coming to Lawrence.

Sally Piller, the owner of a Lawrence gallery where Garcia-Nunez exhibited his paintings, said Mackey acted as a business agent for the artist.

"She was very beautiful, and he referred to her as his angel and his muse," she said. "He seemed very sweet to me. . He did a beautiful portrait of her that was in the gallery."

Piller described Garcia-Nunez, who also went by the name Fito Garche, as a talented artist who employed unusual spiritual imagery.

"Some pieces were playful, some were visceral with a lot of religious imagery that did have blood in it," she said.

It wasn't until after Piller agreed to have a show for Garcia-Nunez's work earlier this year that she learned about his criminal past. He was sentenced in 2005 on assault and burglary charges, was incarcerated and released on parole in August 2006.

The Lawrence Journal-World reported that prosecutors charged Garcia-Nunez after he assaulted a 29-year-old former girlfriend in her home in 2004. The police report stated he choked and beat her, and then cut her arm with a knife before she was able to flee.

"I know his previous problems were a result of his alcohol abuse," Piller said. "He never drank at the openings and seemed to be trying to turn his life around.

"He was very mild-mannered, very friendly, even affectionate. He was very enthusiastic about his painting."

Still, the gallery owner said she was troubled by the relationship between Garcia-Nunez and Mackey.

"I've got to say, I was worried," she said. "I was surprised he'd have a relationship with her given that he had this in his past."

Brungardt said she had met Garcia-Nunez but declined to comment further, wanting instead to focus on her child's legacy.

Mackey graduated in 2000 from Hays High School.

"She was a very good singer and attended KU on a vocal music scholarship," Brungardt said. "She also was in music theater in high school and a dancer all through her K-12 years."

Mackey's academic career shifted two years after entering college when she took a course in the women's studies department.

Sara Burris, a correspondent for Rock the Trail, a project sponsored by Rock the Vote, said she first met Mackey at the KU Gay/Straight Alliance about 2002.

"Never was there a more caring, more compassionate, more brilliant and hilarious woman with each of those qualities and more all wrapped into the heart of one activist," Burris posted on her blog.

The two worked together in political campaigns, including the election of Democratic U.S. Rep. Nancy Boyda of Kansas in 2006. Later, Mackey was a lobbyist in Topeka for gay and lesbian civil rights.

"It was hard to believe how young Jana was," said state Sen. Laura Kelly, a Topeka Democrat. "She was so poised and savvy and determined as a lobbyist for causes that are very sensitive. I was very impressed with her."

Tom Witt, the chairman of the Kansas Equality Coalition, said Mackey's decision to enroll in law school was an extension of her work combating discrimination.

"She believed passionately in what she was doing and was going to law school to get a degree and fight for legal rights for women, gays and lesbians and anybody she felt was oppressed," he said. "She was always willing to step into the fight."

Funeral services for Mackey will be 2 p.m. Wednesday in Liberty Hall, Lawrence.

In addition to her mother, she is survived by her father, Mike Mackey, and brothers Todd and Travis.