It was just after midnight on Sept. 18, 2003, when a Prince George's County police dispatcher broadcast the call: Several teenagers in a van were tampering with a car in the parking lot of a Forestville apartment complex.

Four county officers in marked vehicles responded quickly. Cpl. Thomas Hart, a county police detective, also arrived, in his unmarked 1994 Pontiac Grand Prix. Chasing the van west on Pennsylvania Avenue, he never turned on his emergency lights and siren, even as both vehicles reached speeds of at least 80 mph, according to a civil lawsuit and Hart.

Just across the District line, the van smashed into a 1991 Ford Tempo. The impact killed the Tempo's driver, Lazaro Luis Quinones, a 46-year-old hotel employee and a married father of two boys.

The van driver ran. Hart drove after him, chased him down and turned him over to other officers.

Then he drove away.

Hart wasn't on duty that night. According to a Prince George's police report and the civil suit brought by Quinones's family, Hart was moonlighting that night as a private security officer for two apartment buildings and a condominium complex in Capitol Heights, about three miles from Forestville. Hart said he ended his moonlighting shift about an hour before the pursuit.

The D.C. police detective who investigated the fatal crash later said in a deposition that he had to ask a Prince George's officer, a sergeant and a captain to call Hart and have him return to the scene. Prince George's police never reviewed Hart's actions. A county police lieutenant said in a deposition that he decided that Hart wasn't involved in a police pursuit because he didn't use his lights and siren. Neither Hart nor any of his supervisors filed any reports or filled out any forms, both police and Hart said.

The incident is the latest of several that highlight the widespread practice of moonlighting by Prince George's officers -- and the questions about their accountability when they are involved in controversies. If Hart had been on duty, his actions almost certainly would have drawn the scrutiny of police supervisors, officials said.

The lawsuit filed by attorney Terrell N. Roberts III on behalf of Quinones's widow alleges that Hart, Prince George's County, the four on-duty officers involved in the incident and the management companies for which Hart was working were responsible for his wrongful death.

Alfreda Quinones, 47, said her husband had been working in the laundry room at the Omni Shoreham Hotel in the District for five months -- one month short of being eligible for life insurance.

Between Lazaro Quinones's $28,000 annual salary and the $35,000 she receives as a clerical worker, their family could afford the mortgage on their townhouse in Landover.

Now, Quinones said she has exhausted the family's savings. "I'm just living paycheck to paycheck," she said.

In an interview with The Washington Post, Hart, 39, said he did nothing wrong.

"I felt bad" about the accident, Hart said. "I didn't feel responsible, though. I didn't feel I did anything wrong that night. Things happen all the time.

"There's only two ways these things end -- an accident or he [the suspect] pulls over," Hart said. "If someone's driving 80 miles an hour through red lights, chances are he'll hit someone."

The police department's general orders require officers to activate their emergency lights and siren when they begin a high-speed pursuit.

Hart said he didn't turn on his emergency lights and siren because he was trying to hide from the van's driver and because the incident unfolded quickly, over a little more than a minute.

Barbara Hamm, a Prince George's police spokeswoman, said department policy mandates an internal review if a county officer engages in a high-speed pursuit that ends in a fatality. Even if the officer is off duty, the policy applies once that officer takes police action, she said.

Hamm said she could not comment on the incident involving Hart because of the lawsuit.

Percy Alston, president of the union that represents Prince George's police officers, estimated that at least 70 percent of the department's 1,350 sworn officers moonlight, primarily as security officers for convenience stores, restaurants, banks and housing complexes. Officers often are paid $30 or more an hour for such jobs, a rate above many police salaries.

The moonlighting officers, who usually are required by the department to work their second jobs in uniform, provide increased police visibility, Alston said.

"It's almost an additional [police] force on the street," Alston said.

Secondary jobs also help many officers make ends meet in an area with high housing prices, Alston said.

But Redmond Barnes of the People's Coalition for Police Accountability, a group that advocates reform of the Prince George's police, said many officers do not believe they have to answer to the police department while they are working secondary jobs.

"They are not accountable to anyone except themselves in those situations," said Barnes, who noted that several controversial incidents involving moonlighting officers have occurred in recent years.

In 1999, Cpl. Brian C. Catlett, moonlighting as a security officer, fatally shot a college student who allegedly grabbed for another officer's gun after a dance outside a Lanham Hills fire station. A Circuit Court judge acquitted Catlett of involuntary manslaughter and reckless endangerment. In 2003, the county agreed to pay $200,000 to the student's family to settle a civil lawsuit.

In 2000, attorneys for the county settled a federal civil lawsuit brought by a young man and a young woman who alleged they had been brutalized by a county police officer who was moonlighting at a Lanham restaurant.

In a civil trial that ended with a hung jury, Devon Zuchelli testified that Cpl. Devin C. White shoved him and pepper-sprayed him when he tried to reenter a Red Lobster restaurant after White told him he could not come back in because the restaurant was closing. Zuchelli's former girlfriend, Sheri Lynn Papa, testified that White kicked her and hit her on the head, knocking her unconscious. White testified that he did not use excessive force.

The amount of the settlement was not disclosed, at the insistence of county attorneys.

Joseph Ryan, chairman of the criminal justice program at Pace University in New York, said officers should not respond to police calls when they are moonlighting because of accountability questions.

"When you're off duty, you are a private citizen, and you shouldn't be engaging in police chases," said Ryan, a retired New York City police officer.

Officials with two police departments neighboring Prince George's said a police pursuit that ended in a fatal accident would be investigated by their departments, even if the officer involved was moonlighting or off duty.

"Absolutely," said Capt. Rodney Parks of the D.C. police department's Office of Professional Responsibility and Quality Assurance unit. Montgomery County police also would document and review such a pursuit, said Lt. Eric Burnett.

Hart said he began moonlighting for the two Capitol Heights apartment buildings and the condominium complex seven years ago, part of a group of about a half-dozen officers who work for them. The group is organized by Cpl. Edward S. Finn, who has been investigated at least four times in the past five years for various forms of misconduct.

In each instance, county police found no wrongdoing.

In a sworn deposition given in April in connection with the Hart lawsuit, Finn testified that he schedules Hart and other officers to work as private security officers in six-hour shifts. Management for two of the complexes each pays officers $15 an hour, and the third complex pays a little less, Finn testified.

In 2000 and 2001, representatives of the housing complexes sent letters to police officials praising the moonlighting officers.

Executives with the housing complexes did not return phone calls from The Post.

Hart said in the interview that he had been moonlighting on the evening of the accident, had completed his six-hour security shift and had been "hanging around" for about an hour when he heard the radio call for the suspicious van.

Hart said he saw the teenage driver of the van "ram" two police cruisers. The van's driver was not charged with assault; Hart said someone must have "dropped the ball." According to a Prince George's police report, Hart said on the night of the incident that he would obtain an assault warrant for the driver.

Like other area police departments, Prince George's police have strict rules governing when officers are allowed to engage in a high-speed chase. Officers are supposed to pursue suspects at high speeds across state lines only when they believe the suspect has committed a felony involving the use of or threat of physical force or violence, according to the police department's general orders.

Asked why he didn't stay to give his account of the incident to investigators, Hart said: "We didn't even know who was handling it. I was done at that point, done. What am I supposed to do?"

Alfreda Quinones's husband was killed in 2003 when a van being chased by an off-duty Prince George's police officer hit the vehicle Lazaro Luis Quinones was driving in the District.Since Lazaro Luis Quinones's death, Alfreda Quinones says she and sons Richard, left, and Wille are "living paycheck to paycheck."