An 18-year-old Northwest Washington man was formally charged yesterday with involuntary manslaughter in connection with the shooting of a 17-year-old student at Spingarn High School on Wednesday.

Michael Joseph Pratt, 18, of 815 21st St. NE, was released in his mother's custody by D.C. Superior Court Judge Iraline Barnes yesterday, pending a prliminary hearing Sept. 30.

After reviewing police evidence in the case, the U.S. attorney's office decided to prosecute Pratt on the involuntary manslaughter charge. Prosecutors apparently agreed with police that the shooting was accidental and did not stem from an argument as several eyewitnesses told reporters Wednesday.

Involuntary maslaughter, according to one prosecutor, is the "unlawful killing of a human beign without malice -- it may be a killing committed without a specific intent to kill or even without the specific intent to inflict the injury which causes death."

Pratt was arrested by police at Spingarn High School shortly after the 10:30 a.m. shooting. According to police accounts, Pratt and the dead youth, Adrian (Ajax) Precia, were among about 50 students and nine school officials who were gathered in the school's auditorium for registration. s

Pratt, Precia and several other students, police said, were sitting in the front row of the auditorium, passing around a .25-caliber pistol that a third student had brought to school with him when the gun went off, Fatally injuring Precia.

Following the shooting, D.C. Deputy Police Chief Alfonso Gibson, commander of the department's criminal investigations division, said there was "absolutely no evidence of an argument" among the youths, and that all the youths involved were friends.

However, several eyewitnesses, students in the auditorium at the time, said Wednesday that they believed the shooting was precipitated by an argument between Pratt and Precia: "one dude said he'd shoot Ajax and Ajax say, 'no you won't,'" a 17-year-old student told The Washington Post. "then the gun went off."

In response to the shooting, D.C. City Council Chairman Arrington Dixon said yesterday that "this kind o f incident in our schools is intolerable," and that he would propose emergency legislation to give school officials better control over who can gain access to D.C. public schools by locking some outside doors to the buildings.

Dixon said the legislation will be bought before the council on Tuesday that would require changes in the city's fire code, which currently prohibits locked doors during school hours, He said he hoped this would help resolve the city's lingering problems with in-school violence.

Meanwhile, following an argument over 25 cents at Woodson Senior High School in Northeast Washington, two 17-year-old students were arrested yesterday afternoon and charged with assault.

Police said that after the disagreement, one student stabbed another in the back with a knife. Seeing this, a third student threw a bottle at the knife-wielding youth, cutting him. Both students were treated for their injuries and then released from D.C. General Hospital.