Robert M. Sanchez was discussed on KLSX Los Angeles radio last night and apparently he had a coterie of teen train groupies whom he texted often. The prevailing story is that Sanchez was texting one of them and, thus, took his mind off what he was doing, all of which lead to a disaster that took the lives of himself and 25 others.

Los Angeles- Those who knew Robert M. Sanchez say he was a relentlessly upbeat man with a passion for trains and Italian greyhounds. At the same time, the Metrolink engineer led a solitary life in recent years and was intensely private, sharing little about a past that included tragedy and run-ins with the law.

Sanchez died Friday at the helm of a Metrolink train after apparently failing to stop at a signal near Chatsworth and colliding with an oncoming Union Pacific train. The crash, the worst in modern California history, killed 24 others and injured 135.

Investigators on Tuesday said they had ruled out train and track failure in the accident, and are close to ruling out signal failure. They said they are now focusing on Sanchez and the long days engineers must work, which include lengthy breaks during non-peak hours.

“Split schedules are something that are a great concern to us,” said Kitty Higgins, a National Transportation Safety Board member. She said the agency also would look into a news report that Sanchez was involved in a fatal crash with a pedestrian earlier this month.

In the years before his death, Sanchez led a nomadic life, with public records showing addresses in Oregon, Colorado, Nevada, Arizona, Nebraska and California.

In 2000, he and Daniel Charles Burton, a waiter, bought a home in Crestline.

Burton moved to California from West Haven, Conn., his family said, seeking better weather and the freedom to be gay.

No one in Burton’s family knows how the two men met, but Burton and Sanchez ended up living together in Studio City before moving to the San Bernardino Mountains.

On Feb. 14, 2003, Burton hanged himself in the garage of their home.

“Rob, Happy Valentine’s Day,” read a note Burton left behind that his sister Carolann Peschell kept. “I love you. Please take care of yourself and Ignatia. I love you both very much. Daniel.”

Ignatia was the greyhound the men owned.

The coroner’s report showed that Burton tested positive for HIV. According to the report, Sanchez told investigators that he and Burton had been arguing before the suicide, and Sanchez told Burton that they should break up.

Even before the suicide, Sanchez was having problems.

In 2002, he was arrested on suspicion of shoplifting a video game component from Costco, said Wilson Wong, his former attorney.

Initially charged with a felony, Sanchez pleaded guilty to a misdemeanor charge, paid a fine and served 90 days in jail on weekends, Wong said.

“When the incident happened, he was going through some personal issues — he didn’t tell me what they were,” Wong said. “He said that’s the reason he wasn’t able to make good judgments. He said a lot of things were going on that caused him to make stupid mistakes.”

Sanchez had three minor traffic citations between 2001 and 2005, including speeding and failure to wear a seat belt. He also had a federal tax lien filed against him in 1991 for $6,054 and a Riverside County tax lien for $1,205 filed in 2006, records show. Both were resolved.

After Burton’s death, Sanchez rarely returned to Crestline. He bought a house in Menifee, near Temecula. At the same time he became increasingly interested in Italian greyhounds. That’s when he met Lilian Barber.

“He bought an Italian greyhound as a pet and wanted to breed her,” said Barber, 77, of Murrieta, who has written four books on the small, sleek breed. “He called me and asked if I knew anyone in the area who had a male, so I invited him down to talk about the breed.”

The two began a friendship in which Sanchez, 44, would take Barber to lunch almost every week, sometimes spending the entire day with her.

“He loved his job but always worried that he didn’t have enough seniority and feared they would take his route away,” Barber said.

The NTSB said Tuesday that Sanchez was hired by Union Pacific in 1996. In 1998, he went to work for Amtrak, then he was hired by a contractor to work for Metrolink in 2005.

Sanchez would take Barber to lunch at Thai, Brazilian and other ethnic restaurants. He’d come over and help her husband with yardwork. And he always promised to take them up to Crestline.

“He talked a lot about Daniel and said they had bought the house together,” Barber said, adding that he never mentioned that Daniel had died. “He loved animals and used to talk about being a kid and being involved with 4-H.”

He would come for lunch and stay past dinner. Still, he was reluctant to talk about much besides dogs and trains.

“I did wonder about him,” Barber said. “Why would this man in his 40s want to hang around a lady in her 70s?”

Sanchez accompanied Barber to dog shows, including one in San Francisco to which he wore a tuxedo.

“That was unusual,” she said.

Barber said that she has diabetes and that Sanchez told her he took diabetes medication as well. She said she couldn’t imagine Sanchez doing anything irresponsible while driving the train, and wondered whether perhaps he “may have had a diabetic shock.”

In 2006, Sanchez moved into a modest, two-story home in La Crescenta along with his four greyhounds.

A neighbor there, Oliver Amelsberg, 83, described Sanchez as polite but guarded, someone who liked talking about trains over the backyard fence but didn’t reveal much about himself. And, like Barber, he also found Sanchez “different” but likable.

“He was a good man,” he said. “He acted and talked like a responsible person.”

Amelsberg said Sanchez once told him that he knew some teenagers enamored with trains that he’d occasionally wave to on his route.

“He only said that once, but I thought about it when they mentioned they were sending messages” over cellphones, Amelsberg said.

Investigators are looking into reports that Sanchez may have been text messaging a group of teenage rail enthusiasts just before the accident, and the NTSB said Tuesday that it had subpoenaed cellphone records to examine the engineer’s text messages.

As Sanchez settled into his La Crescenta house, his visits to Barber began drying up.

“He called me before Christmas and said, ‘I am on my way down, let’s go to lunch,’ but I told him I didn’t have time to get ready and he got kind of short with me and hung up,” she recalled. “It didn’t seem very important at the time, but now it does because it would have been the last time I saw him.”

Barber reflected a moment.

“He was so alive and always so up,” she said. “I never met anyone so up. That’s why it’s so difficult to imagine that Rob is dead.”