Prince George's County State's Attorney Arthur A. Marshall yesterday reinstated his chief deputy, Joseph C. Sauerwein, after a four-day suspension, but said he would either charge or fine Sauerwein for his role in two hit-and-run traffic accidents last April.

Marshall said a week-long investigation of the Sauerwein incidents convinced him that the 43-year-old deputy prosecutor was the driver of a car that caused $1,200 worth of damage to two vehicles in a hit-and-run spree on the night of April 26 and that Sauerwein had been drinking before he took the wheel.

"The proper thing to do under the circumstances would be to prosecute him and allow him to defend himself," Marshall said. "However, we are waiting for a little more evidence. The last thing I want is to prosecute Sauerwein when we can't convict him."

Marshall said that police investigating the accidents had not compiled enough evidence to charge Sauerwein with ramming a parked car, and that a decision had not been made on whether to charge Sauerwein with leaving the scene of the second hit-and-run.

According to Marshall, the police investigating the accidents, following a report in The Washington Post last week, did not interview Sauerwein or the passenger in his car during driving spree, Ronald H. Cooper.

In explaining his decision to lift Sauerwein's suspension, Marshall said the investigation showed that his deputy did not attempt to use influence to avoid being charged in the two accidents. He said Sauerwein was guilty of "a gross error in judgment," but added: "I would hope he has learned his lesson."

Last week, while hinting that he would not fire Sauerwein, Marshall has said: "I don't recall Ted Kennedy having his job changed after Chappaquiddick."

If he decides not to charge Sauerwein, Marshall said, he would take administrative action and fine Sauerwein up to $1,000.

Marshall said the internal investigation showed Sauerwein paid the owners of both vehicles he struct, in one case giving an owner of a pickup truck, Thomas Hudson $500 for what Marshall said was $60 worth of damage.

"Apparently he used $500 rather than the office of the state's attorney," Marshall said.

According to police reports and witnesses, the accidents followed a luncheon for Marshall's staff at a Camp Springs restaurant. Sauerwein and Cooper spent the afternoon drinking at the restaurant and at a striptease bar across the street.

While driving away from the bar, Sauerwein struck a 1969 Camaro that was parked legally near the intersection of Allentown Way and Old Branch Avenue, then sped onto the Beltway, where he sideswiped the Ford pickup driven by Hudson.

Sauerwein stopped his car, according to witnesses and police reports, only after he had spun off a Beltway ramp and was chased down by Hudson near the intersection of Pennsylvania Avenue and Westphalia Road.

Later, Sauerwein reminded a police officer investigating the second accident that he would be "embarrassed" by charges, according to the officer.

The officer who investigated the first accident, William Brooks, originally told reporters that Sauerwein had denied being the driver. Marshall said yesterday, however, that his "best information" was that Brooks had never spoken to Sauerwein.

Police officials said yesterday that an investigation of the officers' conduct in investigating the two accidents had not yet been completed.

Sauerwein could not be reached for comment. His attorney, Edward P. Camus, refused comment.