By Amy Silverman
By Olivia LaVecchia
By Monica Alonzo and Stephen Lemons
By Chris Parker
By Michael Lacey
By Weston Phippen
"My guy was getting death threats, even though he hadn't been charged with a thing," Piccarreta says. "I thought, in this country, you at least have to be arrested before everyone thinks you're guilty.
"Though Martinez had clammed up, the detectives had many leads to follow. They tried to work the ubiquitous drug angle, but no solid link ever developed.
Investigators began to speculate that Martinez's oft-demonstrated bad temper, intensified by hours of pounding Bud Lights, had caused him to murder--first Eddie Posada and then a sleeping Sergio Tapia.
One of many bona fide leads in the case was Martinez's girlfriend, Nicole Foster.
Foster began dating Martinez in early 1994. She was 20 years old. Her friends describe her as a sweet, intelligent person, but say her naivet sometimes blinds her. (Foster could not be reached for this story. She is said to be attending college, and apparently is still dating Martinez.)
Foster told investigators that Martinez recently had told her he'd attended the fateful desert party. That surprised her, she said, because the couple had spent much of the weekend together and he'd never mentioned it.
A few hours after that interview, Foster called a detective with important new details. She said that on the evening after the murders, Martinez had gone from his house to his pickup to get a gun. When he returned, he closed all the windows in the house.
A few days later, however, Foster told the detective she'd been mistaken. She said Martinez had retrieved a cassette tape, not a gun. She apologized for the error.
The detectives pieced together Martinez's movements after he'd left the party scene. A Douglas man on his morning stroll said he'd seen Martinez drive by about 5:30 or 6 on the fatal morning. He noted that a mesquite branch was dragging beneath the bed of Martinez's pickup.
Another sighting came about 90 minutes later, on Border Road near Bisbee. Why Martinez took this remote dirt road toward Sierra Vista remains a mystery. What happened there isn't.
Robyn Giacoletti and her daughter were driving to work in Bisbee that morning about 7:40. The two came upon a red Chevy pickup that had veered off the road and was enmeshed in a barbed-wire fence. They asked the driver if he needed help. The man--Mark Martinez--declined their offer.
One of them jotted down his license-plate number as Martinez extricated his truck from the wire and drove on past their car. A few minutes later, however, they saw his pickup again. It had a flat tire. The Giacolettis again stopped.
"I offered to take him to my place of employment so he could call for help," Robyn Giacoletti said later in a witness statement. "He seemed very hesitant. He said several times, 'I have to get to the fort for my shots.' He seemed very apprehensive and was sweaty. He talked very fast. He refused to allow me to call for help.
"The encounter troubled Robyn Giacoletti, who reported the incident to a Bisbee police officer before she reported to work.
Martinez finally made it to Sierra Vista, probably around 8:30 a.m. He called a friend named Shawn Martinez--no relation. Martinez hadn't spoken with Shawn in ages, but he asked to borrow her car for the day while a detailing shop performed cosmetic work on his newly damaged Chevy.
Shawn agreed, and met him at the shop. There, she told police, Martinez loaded a briefcase and other "stuff"--including an empty black holster--into her car.
Later, she told a friend that Martinez had said he'd been up all night partying.Martinez took her to work, then headed to adjacent Fort Huachuca for his 10 a.m. doctor's appointment. He needed shots for his El Salvador assignment. A nurse recalled that the agent "smelled like a brewery.
"Martinez shopped for new clothes at a Sierra Vista store. Sometime after noon, he checked into the Thunder Mountain Inn. The price for one night was $53.
The housekeeper wasn't finished cleaning Martinez's room, so she went about her business as he reclined on the bed. She also recalled he was "weird-acting and looked like he had been drinking all night.
"He told her he planned to stay three nights, or through the weekend. This was odd, because he had planned to go to El Paso the next day, Saturday.
But Martinez left the hotel at about 4:30 p.m., and picked up Shawn Martinez at work. He was wearing new clothes, she later told sheriff's detectives.
The two drove to the detailing shop, where the tidied-up Chevy was ready. They had a quick bite to eat, after which Mark Martinez returned to Douglas.
He then spent that night partying quietly with Nicole Foster and two other friends. He canceled his long-planned trip to El Paso, and spent the rest of the weekend drinking beer and watching movies.
One corner of Mike Piccarreta's airy law office in downtown Tucson is devoted to mementos from his impressive career,
There are keepsakes from the mid-1980s, when Piccarreta earned praise for his effective defense of church workers and other activists charged with harboring illegal aliens.
And there's a U.S. Border Patrol hat and nameplate engraved with the name Michael Elmer.