Eighteen years after Jason Mosley was shot to death outside a Fulton Street housing complex the night before his City Hall wedding, San Francisco police say they have arrested a suspect. What they have not produced is a motive — or a public accounting of how they broke the case.

SFPD's Cold Case Unit says it identified Derreyl Goode, 40, in the April 2008 killing of the 28-year-old Mosley, traced him to Las Vegas, and had him arrested in Los Angeles on Aug. 17 with help from a federal fugitive task force. Goode is booked for homicide and awaiting transfer to San Francisco, where he has yet to appear in court. But police have declined to describe the evidence, no motive has been offered, and the family's nearly two-decade belief that Mosley was killed by mistake remains unanswered. An arrest, in other words, has reopened the oldest question in the case without resolving it.

SFPD's Cold Case Unit named Derreyl Goode, 40, a Las Vegas resident, as the suspect in the April 27, 2008 killing of the 28-year-old Mosley. Working with a federal fugitive task force, detectives located Goode and arrested him in the Los Angeles area on Aug. 17, according to KTVU (external source, opens in a new tab) and the San Francisco Chronicle. He was handed to the Los Angeles County Sheriff's Department, met there by SFPD investigators, and booked on an outstanding homicide warrant. Per KTVU, he is to be arraigned once he reaches San Francisco County. (SFPD and some outlets spell the victim's surname "Mosely"; his family, as quoted by SFGATE, uses "Mosley.")

The shooting happened at a seam between neighborhoods that outlets label differently — the San Francisco Chronicle (external source, opens in a new tab) puts the Fulton Street address in Hayes Valley, while SFGATE calls it the Western Addition — but everyone agrees on the geography that makes it wrench: the scene sat roughly three blocks from the City Hall rotunda where Mosley was to be married the next morning. That Sunday evening, he was at the home where he cared for his elderly grandmother when the doorbell rang. He stepped outside a little after 6 p.m. and was shot; two security guards returned fire, and the gunman dropped his weapon and fled, as SFGATE recounted from the Examiner's 2008 reporting. His pregnant fiancée, Alejandra Lara, spent what should have been her wedding day grieving alongside his mother.

How the case broke loose is exactly what police won't say. SFPD spokesperson Robert Rueca told KTVU that investigators had located evidence he would not describe, and that it supplied the probable cause behind the arrest warrant. He tied the renewed movement in part to the city's falling violent-crime numbers, which he said give the cold-case unit more people, time and resources to work decades-old files.

That opacity is not a small thing in a case this old. The arrest rests on a police-obtained warrant, not a filed prosecution: Goode has not yet appeared before a San Francisco judge, and no charging document has been made public. SFGATE reported he is jailed in Los Angeles County without bail while the transfer runs. An identification made 18 years on, in an investigation the department itself calls "open," will still have to survive discovery and cross-examination before it becomes a conviction.

An arrest also does not settle the theory Mosley's relatives have carried since 2008 — that he was never the intended target. In their account to SFGATE, the family said he had no gang ties and that the only explanation they can reach is mistaken identity. If detectives now believe they know who fired, they have not said publicly whether they believe they know why, or whether that mistaken-identity account still squares with the evidence they won't describe.

The Dissent recently documented how quickly a cold-case arrest can unravel at the courthouse: SFPD arrested a Sunnydale murder suspect on a warrant only to watch the case collapse within 48 hours when prosecutors declined to file. The Mosley arrest is at an even earlier stage — an out-of-county booking on a police warrant, no San Francisco court date yet, no charge on the record. The department's homicide detail is still soliciting tips, by phone and by anonymous text through TIP411. The answer to the question Mosley's mother has asked for 18 years may not arrive until a courtroom forces it.