A 26-year-old man who skipped bond on charges of killing an 8-year-old Montgomery County boy in a drunken-driving incident last year has been arrested in Las Vegas, FBI and Montgomery County Sheriff's Department officials said yesterday.

Misael Cordova Iraheta, an illegal immigrant from El Salvador, was arrested without incident at 5:24 p.m. Thursday while sitting in a pickup outside an apartment building near downtown Las Vegas, said Sgt. Ronald Frye, head of the fugitive squad for the sheriff's department.

Frye said Iraheta initially showed FBI agents and Las Vegas police an identification card with the name of Wilfredo Sanabria. But when authorities produced a photograph of Iraheta sent by Montgomery officials, Frye said, Iraheta replied, "Yes, that's me."

According to Frye, Iraheta then said to police, "Boy, I'm in trouble. The little boy died, didn't he?"

Late yesterday, Iraheta was being held in the Clark County jail awaiting extradition to Maryland, officials said. If Iraheta waives extradition, he could be returned to Montgomery County in a few weeks, Frye said.

The sheriff's department and the FBI have been tracking Iraheta since September, when he failed to appear for trial on eight charges, including vehicular homicide while intoxicated. Iraheta, a construction laborer, was arrested April 21, 1989, and charged with the killing of Joshua Maggin, of Potomac, in a hit-and-run accident.

Iraheta was released from the county jail in July 1989, after a Circuit Court judge lowered his $100,000 bond to $5,000. His release and subsequent failure to appear for a court hearing angered the boy's parents, who criticized the criminal justice system for what they called negligence.

Police said Iraheta, whose blood alcohol content at the time of his arrest was slightly less than the 0.1 percent level at which a person is considered legally intoxicated, slammed into the bicycle Joshua was riding.

Police contend that Iraheta's blood alcohol content was higher at the time of the accident.

Iraheta, police said, drove away after running into the boy, but "freely admitted being involved in the accident" when arrested a few hours later.