SAN JOSE — A woman had a protective order against a man who fatally shot her, then shot and killed himself in the parking lot of a Denny’s on Monday night, according to San Jose police.

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The presumed murder-suicide was part of a violent night in the neighborhood south of downtown bounded by Highway 87 and Interstate 280. A few hours later, half a mile away from the restaurant, a man was shot to death in an unrelated attack.

In the diner incident, the violent episode unfolded rapidly around 10:50 p.m. in Denny’s parking lot at East Alma Avenue and South First Street. Police say that at some point before the fatal gunshots, the shooter — armed with an AR pistol that fires .223 rifle rounds — also fired at a security guard but missed.

Police said the victim and shooter had been in a previous dating relationship, but it was not immediately clear how much time had passed since that relationship ended, or how the two came into contact with each other at Denny’s.

Neither of the deceased were identified as of Tuesday afternoon, pending notification of their next of kin.

Witnesses described a frantic scene in which some patrons or employees sought protection in the restaurant’s walk-in refrigerator amid the gunfire.

On Tuesday morning, the diner was bustling with the breakfast rush. Remnants of crime scene tape littered the parking lot, but otherwise, there were few signs of the tragedy that unfolded the previous night. A hostess referred questions about the shooting to Denny’s corporate office.

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Additional details, including a formal motive, were not immediately available.

Around 2:28 a.m., police were called to the 300 block of Keyes Street near Spartan Stadium for reports of a shooting, and responding officers found a man suffering from at least one gunshot wound. He was pronounced dead at the scene.

His identity was not immediately released pending notification of relatives. Suspect and motive information were not released by police Tuesday.

Police are confident there is no connection between the night’s shootings, which marked the city’s fourth and fifth homicides of the year. Five homicides were also recorded by the same point in 2017.

Anyone with information about either shooting can contact the SJPD homicide unit at 408-277-5283. Tips about Denny’s shooting can be directed to Detective Sgt. Bert Milliken or Detective Raul Corral, and tips about the Keyes Street shooting can contact Detective Sgt. John Barg or Detective Wayne Smith.

Tipsters can also contact Silicon Valley Crime Stoppers at 408-947-STOP or at svcrimestoppers.org, and may become eligible for a cash reward.