Nicholas Callen, 24, of Tara Hills, California, was found dead at a home on Cornelius Drive on March 31, 2014. Deputies from the Contra Costa County Sheriff’s Office performed CPR until paramedics arrived, but Callen was pronounced dead at the scene; the cause of death was a fatal gunshot wound.

Two men were arrested in connection with the homicide. Michael McQueen, 28, of Pinole, was arrested by the U.S. Marshals Service in Sonoma. Kyle Navarro, 20, of El Sobrante, surrendered to the Contra Costa County Jail in Martinez on April 23, 2014, after an arrest warrant was issued; both men were booked on murder charges and held on $2 million bail. Reports linked part of the motive to McQueen’s romantic feelings for Callen’s girlfriend.

If anyone knew Nicholas, his movements that day, or has information about the relationships involved, please share what is known with investigators.