The Howard County man accused of slaying his girlfriend and her son was ordered held without bond yesterday and will undergo extensive psychiatric testing.

Howard County District Court Judge Lenore R. Gelfman ruled that Melvin L. McMains, 36, who is charged with two counts of first-degree murder in Sunday's killings, should remain incarcerated "in the interest of public safety."

She also ordered that McMains be taken to the Clifton T. Perkins Hospital Center, a maximum-security facility for the criminally insane in Jessup, for further psychiatric evaluation based on the recommendations of psychiatrists who examined McMains Sunday evening.

McMains, a bus mechanic, is accused of killing Caria A. Roth, 30, and Christopher Roth, 8, both of whom lived with him at the Whiskey Bottom Apartments in North Laurel.

Caria Roth, a bartender, was shot in the head with a .45-caliber semiautomatic handgun.

Her son was repeatedly stabbed, police said. They were both found dead in their living room. Christopher's 8-week-old pit bull puppy also was shot to death.

After asking a neighbor to call police about 8:30 Sunday morning, McMains allegedly told police at the scene, "I have sinned and killed them all."

Police said that in later interviews McMains said he had killed Caria and Christopher Roth.

At the bond hearing yesterday morning, McMains spoke in a low voice, stood with his hands clasped in front of him and rocked back and forth whenever he answered the judge's questions.

Asked whether he wanted an attorney, McMains said, "I cannot afford one . . . . I don't need one, I suppose."

McMains also said he was on parole after having been convicted of driving under the influence of alcohol in Anne Arundel County.

Police said they found a small amount of PCP in McMains's apartment and that McMains told them that he smoked the drug Saturday night. Several handguns and hunting knives were also in the apartment, according to police.

A neighbor who said she had been a good friend of Caria Roth's said that McMains is an avid hunter, who had a stuffed boar's head on his living room wall and always kept a knife in a sheath hooked to his belt.

The neighbor, Debra Lazar, 25, said she had known Roth for four years and that Roth had been living with McMains for about six months.

"She seemed happy," Lazar said. "She said he was a really nice guy. She said he was real good to her and Christopher.

"She said she thought she might end up marrying this guy."

Lazar said she last saw the couple Friday evening, when she visited their apartment.

"They seemed fine," she said. "They were sitting there laughing and joking together."

Lazar, who said she gave Christopher the puppy Thursday, described McMains as a "nice guy" who enjoyed taking Christopher on motorcycle rides and to a nearby park.

"I used to go over and borrow sugar . . . and everytime I saw him he greeted me nicely," Lazar said. "He talked about God. He talked down on drugs. He never seemed that he was capable of doing something that crazy."