He had no apparent connection to Oakland lingerie store owner. So why did he allegedly wait outside and kill him at 3 a.m.?

OAKLAND — Police here have arrested a suspect in an ambush-style shooting that targeted two brothers who operated a late-night lingerie store in an area known for prostitution, according to jail records.

But what authorities can’t explain thus far is why it was so important for 30-year-old Christian Mendoza to wait in an alleyway on the 1600 block of Solano Way, then fire several shots into a Toyota Prius, killing 28-year-old Zinatullah Hedayet. The shooting happened around 3:15 a.m. on Dec. 19.

On Monday, police arrested Mendoza on suspicion of murder based on digital evidence, surveillance footage, and witness statements. They’re expected to bring a case to the Alameda County District Attorney this week, authorities said.

The motive, for now, remains a mystery. Police haven’t been able to find any linkage between Mendoza and Hedayet and his brother, who was struck in the arm and survived. When Mendoza was arrested in Oakland on Monday afternoon, he was also booked for allegedly possessing a concealed firearm and drugs in his car, according to the jail booking log.

On Jan. 7, police arrested another suspect, a 31-year-old man, on suspicion of murder and conspiracy. But that man was released without charges after providing a statement, authorities said. It’s unclear whether he gave police anything useful.

Mendoza, by contrast, refused to talk with investigators when he was arrested. His arraignment has been tentatively set for Wednesday morning. He is being held without bail at Santa Rita Jail in Dublin, records show.

Police had previously described the shooting as a targeted ambush, where one man waited behind the brothers’ store for as long as 15 minutes, then opened fire when they were in a vulnerable position in their car. The gunman then ran to a waiting getaway vehicle, authorities said.

Both victims operated an East Oakland store on the 1600 block of International Boulevard that sold snacks and drinks, but also see-through lingerie, fishnet clothing, high-heeled faux leather boots and cheap, shiny jewelry, according to its Instagram and Yelp pages. Outside the store, sex workers are known to walk the streets at all hours of the day and night, in a section of International Boulevard known as “The Blade” that spans more than a mile and is arguably the biggest open-air sex market in the Bay Area.

The shop’s Oakland-issued business license expired on New Year’s Eve — 12 days after Hedayet was killed — and its Google page lists it as “permanently closed.”