The man accused of stabbing 68-year-old Todd Stewart to death outside his Martinez home had been released from custody on his own recognizance the day before the killing — and, according to the city's police chief, his home-detention monitor wasn't physically placed on him until the day after.

Marcos Iriarte-Valdez, 36, faces a murder charge in a killing that Martinez police describe as having no known connection to its victim. But the detail drawing scrutiny in Contra Costa County isn't the randomness of the attack — it's the calendar. Iriarte-Valdez was already on pretrial release in a separate burglary case, had just been jailed for allegedly violating the terms of that release, and was let out again roughly 24 hours before Stewart was stabbed on his own front lawn. The sequence raises a pointed question about how the pretrial system weighed his risk — and whether the monitoring meant to manage that risk was even functioning.

Todd Stewart was in his garage on Francis Court, a quiet stretch of single-family homes in Martinez, when a man drove into the court around 5 p.m. on Thursday, Aug. 6. Police Chief Andrew White said the two got into a confrontation "with no known connection to the victim," and that it ended with Stewart stabbed multiple times steps from his front door. He died at the scene. Surveillance video from neighbors captured the attack, including Stewart's screams.

Neighbors described a retiree who was a fixture on the block. "He is a neighbor everybody wishes they had," Galina Pasternak, who lives next door, told NBC Bay Area. She said Stewart had recently retired and was traveling more with his wife; he leaves behind a spouse and two adult daughters.

Investigators moved quickly. White said Martinez police used automated license-plate-recognition technology and tips from residents who recognized the suspect's vehicle to track it down. Officers arrested Iriarte-Valdez on Friday evening at his home, without incident. He is being held at the Contra Costa County jail on bail set above $1.1 million.

It is what happened in the days before the stabbing that has turned a random-seeming crime into an accountability story.

According to Martinez police accounts reported by NBC Bay Area and KTVU, Iriarte-Valdez was on pretrial release tied to residential burglaries that occurred April 29 in Orinda. On Tuesday, Aug. 4, he was taken back into custody for allegedly violating the terms of his home-detention monitoring. The next day, Wednesday, Aug. 5, he was released on his own recognizance and referred back to that same monitoring program. Stewart was killed Thursday.

Then the sharpest detail: White said it appeared Iriarte-Valdez's home-detention monitoring equipment was not actually placed on him until Friday — the day after the homicide, and the day he was arrested for it. County records reviewed by NBC Bay Area also showed he was enrolled in a diversion program for a misdemeanor violation of a protective order.

The case has quickly become a test of a familiar tension in California's pretrial system. "How could this individual, who was just released from custody with no known motive, now be allegedly involved with a vicious homicide?" legal analyst and former prosecutor Steven Clark asked on NBC Bay Area. "Where did the system possibly go wrong in its evaluation of his risk to public safety prior to his continued release on home detention?"

Clark also offered the counterweight that pretrial judges operate under: courts are legally required to find the least restrictive conditions for defendants who have not been convicted. "There's a delicate balance between public safety and the right of the individual for pretrial release because they are presumed to be innocent," he said.

That balance is cold comfort on Francis Court. Pasternak said Stewart's wife had noticed a car parked outside the home for as long as an hour before the attack, assuming its occupant was visiting a neighbor. "I'm glad they arrested him, but it won't bring Todd back," Pasternak told KTVU. "I wish they did not release him."

Neither Martinez police nor Contra Costa County officials have publicly explained who authorized the Aug. 5 release, on what risk assessment, or why the monitoring device went unattached during the window in which Stewart was killed. Those are the questions the county's pretrial apparatus — not just its police department — will have to answer.