In the mug shot taken after Baltimore police charged him with clubbing and slashing to death three children in his extended family last Thursday, Policarpio Espinoza, 22, stares directly into the camera, his face seemingly devoid of emotion.

A seasoned homicide detective told colleagues that the second suspect charged in the killings -- Adan Espinoza Canela, 17, a nephew of Espinoza's -- was "one of the coldest men" he had ever interrogated.

But in interviews Tuesday, relatives who shared their home with the two Mexican immigrants said those images, and the savage nature of the crime, do not square with their perceptions of Espinoza and Espinoza Canela, whom they described as friendly and caring.

Adan Espinoza Canela is a somewhat quiet, responsible son who often brought home pizza to share with his four younger stepbrothers and stepsisters, his father, Victor Espinoza, said.

Victor Espinoza said that his brother, Policarpio Espinoza, is a joker who made friends easily after moving to Baltimore four years ago and that he is sweet and affectionate with children.

"I can't tell you that I know for a fact that they did not do this because I was not with them at the time," Victor Espinoza said. "But I can't believe that they were involved."

Espinoza's wife, Guadalupe Espinoza, who is not the 17-year-old's mother, nodded emphatically. "We just can't assimilate this," she said.

The couple sat across from each other on matching red-velvet couches in the cramped living room of their brick house in Pikesville, about two miles from the Baltimore apartment where the killings occurred. The green-walled room had no decorations, save a candle flickering in front of a large picture of the Virgin Mary propped against a wood cabinet.

Victor Espinoza had arrived home moments earlier, walking up the path to his front door with the slow, heavy gait of a man who is leading his family through a nightmarish ordeal.

It began last Thursday afternoon, when Victor and Policarpio Espinoza's other brother, Ricardo Espinoza, came home from work to find his daughter Lucero Quezada, 8, and son Ricardo Espinoza, 9, lying in pools of blood along with their cousin Alexis Quezada, 10, who also lived in the apartment. One of the children had been decapitated and the two others were nearly beheaded.

A judge has ordered police and attorneys in the case not to comment publicly on it, but a police official, speaking yesterday on the condition he not be identified, said investigators have not determined a motive. The suspects, each charged with three counts of first-degree murder, are being held without bail.

Police said a witness reported seeing the suspects watching the apartment several days before the killings. They said Policarpio Espinoza has told them that he dropped off Espinoza Canela at the apartment Thursday and later saw him emerge shirtless from a window. Police said they found a bloody shirt and towel at the home where the suspects were living.

It was not clear yesterday whether police have determined whose blood was on the shirt. As for Policarpio Espinoza's alleged statement, which was made in Spanish, his attorney has challenged authorities' translation of it.

Victor Espinoza said he could think of no motive for the slayings. Grimacing at some points during the interview and falling into a gloomy silence at others, he appeared conflicted about whether to speak out about the case.

"I just don't know who I can trust now," he said several times, but stressed that neither Adan nor Policarpio had shown signs of being capable of harming a child.

"I left them with my own children many times. And they also watched Ricardo's children from time to time," he said. "There was never any problem."

Victor Espinoza, 37, is the oldest of the brothers, who come from a small town near Veracruz in Mexico. Ricardo who came to the United States first, arriving about seven years ago.

Victor Espinoza followed, moving with his wife to Baltimore about five years ago. He soon started a small business delivering tacos to workers at construction sites in a fleet of vans. He eventually employed Ricardo and Ricardo's wife.

"We all help each other. One month I had trouble paying for my cell phone, and Ricardo lent me money. Another time he called to say, 'It's going to be hard for me to cover my rent,' and I helped him," Victor said.

About four years ago, Policarpio came to the United States and moved in with Victor and Guadalupe's growing family. Victor declined to say how Policarpio and Adan entered the country. A judge said in court Tuesday that the two are here illegally, as were the victims.

Guadalupe, 31, said she took an instant liking to her young brother-in-law Policarpio. "He used to tell me that I was like a mother to him," she said.

Policarpio found work laying concrete with a construction company and would often go out on weekends with Mexican friends he met on the job. They loved to hear live music -- traveling as far as Delaware for concerts, Guadalupe said.

Other times Policarpio and his friends would spend their spare time strolling through a flea market in Laurel.

Victor Espinoza said that his brother occasionally drank beer but that he never knew him to use drugs. Nor did he ever see Espinoza Canela use drugs.

Espinoza Canela arrived about 18 months ago. He is the oldest of five children that Victor Espinoza has with a woman back in Mexico and Victor had not seen him in several years. Nonetheless both Victor and Guadalupe said Adan fit into the household smoothly.

Victor Espinoza offered his son a job in the taco business. Espinoza Canela contributed about $250 a month toward the family's rent and utilities. And after a few months he announced that he wanted to "suffer what everyone else suffers here and find a job of his own," Victor Espinoza said. He soon found work doing yardwork for a landscaper.

Espinoza Canela and Policarpio Espinoza, who shared a room, "were like brothers, they went a lot of places together," Guadalupe said. Often, the 17-year-old would join Policarpio and his friends at a neighborhood pool hall called the Gentleman's Cue.

"He has never given us any problems. He's just a very nice person," Guadalupe said. "They both are."

Victor said he and his brother Ricardo remain close. At a vigil last night outside the apartment where the killings occurred, Victor Espinoza stood behind his brother. Afterward, Espinoza massaged his brother's shoulder as the two, weeping, walked away.

Staff writer Del Quentin Wilber contributed to this report.

Maria Andrea Espejo, center, mother of slain 10-year-old Alexis Quezada, is comforted during a vigil in Baltimore. "I just don't know who I can trust now," says Victor Espinoza, listening during the vigil as his wife, Guadalupe, weeps. His son and brother are suspects.