Execution is going to be a much more visible and sterile experience at San Quentin State Prison from now on.

Prison officials offered the first glimpse of their new lethal injection center Tuesday - one week ahead of a planned execution few think will actually be carried out - and the differences between this stark-white place and the old apple-green gas chamber are marked.

The spacious $853,000 center has three brightly lit witness viewing rooms, and each gives a considerably better view than the cramped gas chamber's lone, poorly illuminated viewing room.

In particular, the main observation room for 12 state officials and 17 media witnesses offers four wide, flat windows looking straight into a roomy, open chamber where the lethal injection gurney sits. This makes every angle of the execution visible - unlike the truncated, partially blocked sightlines of the old center.

On the north side of this main witness room is a smaller, seven-seat room for survivors and friends of the condemned inmate's victims. On the south side is an identical room with seven chairs for relatives and friends of the prisoner. Each of those rooms has two wide windows providing unimpeded views.

Execution in doubt

But it is unclear whether there will be any witnesses at 12:01 a.m. next Wednesday to see rapist-murderer Albert Greenwood Brown, 56, put to death as planned. That's because the execution itself is in doubt.

Capital punishment in California has been blocked since 2006 by two state lawsuits contending improper procedures in planning injections and one federal suit contending that lethal injection is a cruel and unusual punishment. Though an injunction was lifted in one of the state suits Monday and U.S. District Judge Jeremy Fogel of San Jose said Tuesday he will issue a ruling in the federal suit on Friday, there remain several avenues for appeal before an execution can take place.

When he halted all executions in February 2006, Fogel ruled that the state's procedures were so badly flawed, with poorly trained staff working with unclear instructions and little monitoring in a dimly lit chamber, they posed a risk of leaving the dying inmate conscious and in pain at levels that violated the constitutional ban on cruel and unusual punishment.

In response, state officials revised the procedures and built the new death chamber in 2008.

"I don't know how they could simply dismiss the current legal challenges," said Lance Lindsey, executive director of Death Penalty Focus, which opposes capital punishment. "There is no reason to rush."

Proceeding as planned

Nonetheless, the state attorney general's office issued a death warrant for Brown's execution last month, and the prison has been making plans ever since for its first execution in four years. Brown raped and strangled a 15-year-old Riverside girl in 1980.

"We are fully prepared to carry out an execution on Sept. 29," acting Warden Vincent Cullen said Tuesday. "This facility is fully operational."

Unlike the 1937-vintage gas chamber that was tucked behind an ominous-looking iron door, from the outside the squarish new injection center looks as benign as a storage warehouse. It has no outside-looking windows, is painted beige, and is tucked beneath a fortresslike wall, 100 yards to the south of the gas chamber.

Inside the 23-by-10-foot, rectangular chamber where the prisoner will be injected with deadly chemicals, there is room for dozens of people - unlike the 7 1/2-foot-wide gas chamber where six guards had to squeeze by one another, with difficulty. The injection gurney - a converted, lime-green dentist chair onto which the prisoner is strapped down, flat on his back - sits in the middle with plenty of maneuvering room on three sides.

It's the same gurney that has been used in 11 lethal injections since 1996, when the method replaced gas executions in California.

Squeezed together

In the much smaller, octagonal gas chamber, the six execution team members who had to strap the prisoner down and insert intravenous lines into his veins could barely move around one another. There's no chance of that happening in the new execution room, even with new procedures calling for a minimum of 20 execution team members inside and out of the death chamber.

The old gas chamber also had just five small windows separated by thick steel girders. Witnesses were gathered, all together, in a circle around the chamber. In the hazy light and with support pillars in the witness area blocking views, it was difficult to see more than a snippet of what was happening to the condemned man.

Seeing inmate, not viewers

The new injection chamber's views leave little unseen. The main difference is that unlike in the gas chamber, reporters won't be able to directly watch or hear the reactions of witnesses from the victim and inmate rooms to either side.

One major improvement in the new facility is that it has been wired with speakers. The condemned prisoner will be able to broadcast his last words by a wireless microphone held to his lips by one of the executioners.

The old gas chamber is still ready for use if needed, the warden said. But with the official method of execution in California being lethal injection, a prisoner would have to make a special request for gas instead.

Like the new injection room, the old gas chamber was entirely built by inmates.

Chronicle staff writer Bob Egelko contributed to this report.