CONCORD -- Police are investigating a possible murder-suicide involving two longtime partners discovered Monday night, marking the city's second homicide in as many days.

The bodies of Frederik Meurer, 32, of Concord, and 32-year-old Miranda Pretoli were found by officers about 8:30 p.m. after they got a distress call from a home in the 2300 block of Bedford Road, police said.

They found Meurer and Pretoli lying on the floor of the residence, dead from apparent gunshot wounds. Police did not release a motive or the circumstances leading to the shootings, citing an ongoing investigation.

Next-door neighbor Gene Traversaro said he was home when the bodies were found, but he did not hear any noise or commotion suggesting violence. No one else is believed to have been involved in the deaths, which shocked a neighborhood that warmly remembered the pair.

Meurer and Pretoli lived together in a rear building on the property while Meurer's mother lived in the main home, neighbors said. In court records, Meurer described Pretoli as his "life-long partner."

Traversaro, a 30-year resident of the serene street, said he has lived next door to the Meurer family for a quarter-century and described the deceased as well liked in the neighborhood.

"They're wonderful people," Traversaro said. "I get this empty feeling knowing they're gone."

Traversaro said he would occasionally get breakfast with Meurer, an avid camper who frequented grounds up and down the state. He was known in the neighborhood as a friendly face for years.

"He doesn't drive by without honking and saying, 'Hey,' " Traversaro said.

The investigation follows a deadly stabbing late Sunday afternoon that killed 20-year-old Concord resident Richard Gilliam. The man suspected of stabbing him, 19-year-old Joshua Cardone, was arrested at the scene, the parking lot of the Clayton Valley Shopping Center in the 5400 block of Ygnacio Valley Road outside Burger King.

Investigators say Gilliam and Cardone knew each other but are still probing their relationship as well as what prompted the argument that preceded the stabbing. Prosecutors will consider charges Wednesday.

The homicides are the first and second recorded in Concord this year. There were four in 2010 and two in 2009.

Police ask that anyone with knowledge about the Monday evening incident contact Detective Greg Pardella at 925-603-5922 or the Concord police anonymous tip line at 925-603-5836.

Staff writer Malaika Fraley contributed to this story. Contact Robert Salonga at 925-943-8013. Follow him at Twitter.com/robertsalonga.