Brian and Beverly Mauck fit together like two pieces of a puzzle, friends recalled Saturday at a memorial service for the young couple. He was fearless, she was a daredevil; he loved football; she was an athlete.

The couple, who lived in Graham, Pierce County, were found fatally shot in their home Nov. 17. On Tuesday, police arrested a neighbor, Daniel Tavares Jr., 41. He has been charged with aggravated first-degree murder in their deaths. Charging papers said the slayings followed an argument over a $50 debt.

Hundreds of people attended the Saturday memorial service. In a two-hour tribute that overflowed into the hallway at the Federal Way Community Center, friends and family said that though Brian and Beverly Mauck's lives were cut short, they lived life to the fullest.

"They didn't let a moment slip by," said Beverly's sister Jennifer Heilbrun. "They were about trying new things and not caring about who's watching."

Brian Mauck, 30, had an infectious smile, a mischievous sense of adventure and the loudest voice in the room, friends said at the service, calling him a "wild stallion." Beverly Mauck, 28, refused to wear dresses as a child and played on the boys athletic teams in high school.

Many attending wore Seahawks jerseys as a tribute to Brian, a season-ticket holder.

His family hopes the football team will honor him at today's game, and his friends say they will keep his seat reserved for him for the rest of the season.

"They ended their lives like they lived life — together," said Rick Bulman, chaplain for the Pierce County Sheriff's Office, at the service.

"It's a sad end to a sweet love story."

"Brian knew no fear," Bulman said. "We won't talk common sense." At the age of 3, he sneaked off to 7-Eleven to buy candy, crossing two four-lane highways to get there.

As an adult, Brian worked at Emerald Aire, an air-conditioning company in Auburn.

Beverly, who worked at a car dealership, loved sports and had hoped to become a competitive speed skater until her back was injured in a car accident.

The two married in 2006 and traveled the world on scuba-diving trips.

Tavares, the neighbor charged in the Mauck slayings, was released from a Boston-area maximum-security prison in July after serving 16 years for manslaughter; he had killed his mother with a carving knife.

Mitt Romney, the former Massachusetts governor who is seeking the Republican nomination for president, has called on a judge he appointed to resign because the judge freed Tavares from prison.

"They're going to use this in political games," said Beverly's mother, Karen Slater, after the service. "But I want to use them back" to raise awareness about the criminal-justice system that let Tavares go free.

Tavares could face the death penalty if convicted of killing the Maucks.

"All I want to know is he's going to stay in prison for the rest of his life," said Heilbrun, Beverly's sister.

Information from The Associated Press was used in this report.

Sharon Pian Chan: 206-464-2958 or schan@seattletimes.com