The search continued Monday afternoon for a 16-month-old boy whose mother was found dead hours after police had answered a call of an argument between the woman and her husband.

New Mexico state police issued an Amber Alert for the toddler, Justin Black, who was in the apartment when police responded to the initial call of a verbal domestic dispute around 1 p.m. Sunday between Ivan Villa (search) and Kristi Black.

"A husband and wife were arguing," Ruidoso (search) police Detective Jim Biggs said. "They agreed to separate and he left. There wasn't an arrestable offense then because there were no signs of physical violence."

Several hours later, a friend went to the apartment and found 19-year-old Kristi Black's (search) body. Ruidoso police are awaiting the results of an autopsy before making a determination on the cause of death.

Villa and the child, who is not Villa's, were gone. Police on Monday issued a warrant for Villa's arrest on a charge of kidnapping.

Biggs said tips are pouring in but so far nothing has led to Justin Black or Villa.

"We're just getting tons of phone calls," Biggs said. "It's gone nationwide at this point."

Authorities aren't sure what kind of bond or relationship Villa and Justin Black had developed over the six months that Villa had been married to the child's mother.

Villa, 22, has ties to the Houston area, and state police believe he may be headed there, state police Lt. Jimmy Glascock said. Ruidoso police said he also has family in the El Paso, Texas, area, and in California.

The Amber Alert itself went throughout New Mexico and into Texas, but Glascock said the information went nationwide through police channels and groups that put out alerts on missing children.

Villa is 5-foot-11 and 190 pounds with black hair, brown eyes and a goatee. He was believed to be driving a silver or gray 2000 Ford Mustang with New Mexico license plate GBN805, Glascock said.

Justin Black has brown hair and brown eyes.