The superintendent of the State Police said today he was "not happy" that Dontay Carter "slipped through our system" after he allegedly murdered an engineer from Catonsville and twice used the victim's doctored state driver's license to avoid being detained for questioning by state troopers.

"I am not happy that he slipped through our system," said Col. Elmer H. Tippett.

"I have concerns in what happened . . . that we had him. This makes us to again look at our procedures" regarding how potential suspects are questioned by officers of the agency.

One day after Vitalis V. Pilius, the engineer, was abducted from a downtown parking garage, robbed and slain, a state trooper stopped Mr. Carter for speeding and was presented with Mr. Pilius' driver's license bearing Mr. Carter's picture. However, after running a check and learning that Mr. Pilius, a 37-year-old white male, had been reported missing, the trooper allowed the 18-year-old black suspect to drive away with only a warning ticket.

It marked the second time in less than 24 hours last week that state troopers came upon Mr. Carter in possession of the older victim's license and credit cards, yet failed to detain the suspect.

"Supporting your officers is one thing," Colonel Tippett said. "Looking at what happened is another. Whether Mr. Carter jumped into their faces, we're going to take a look at that . . . Mr. Carter was a very good con artist."

An informed source in the State Police said Colonel Tippett "thought the troopers in question didn't do everything right but really did nothing wrong."

"This guy Carter conned all of them and there was a lack of follow-up on the traffic stop," the source said.

But, the source said, the incidents show that the State Police "should stop concentrating on catchy little slogans and giving out tickets and concentrate on basic police work."

"We have two administrative reviews under way," spokesman Chuck Jackson said today. "Officers will review written reports regarding both incidents."

Both reviews will be "quite objective," he said.

"She followed procedures to the fullest extent," Capt. Johnny Hughes, chief public information officer for the state force, said of Trooper Holly Fuller of the Golden Ring barracks, who failed to arrest the suspect last Wednesday. "In fact, she went overboard."

Paige Boinest, a spokesman for Gov. William Donald Schaefer, said today Mr. Schaefer has been briefed about the incidents. "He is deeply concerned," Ms. Boinest said.

About 2 p.m. Feb. 12 in the southbound lanes of Reisterstown Road near Ritters Lane, Trooper Fuller pulled over a rental car operated by a black male now believed to be Mr. Carter.

Mr. Carter is charged in the murder of Mr. Pilius and with the abduction and robbery of two other men.

In the car with Mr. Carter were three other men.

The trooper had clocked the car as traveling at 60 mph in a 45 mph zone.

She approached the car and asked for license and registration, Captain Hughes said.

The driver of the car handed over a license that contained Mr. Carter's picture, but it contained Mr. Pilius' name, date of birth and physical description. Police believe the suspect obtained such a license at the Mondawmin branch of the Motor Vehicle Administration by burning the picture off Mr. Pilius' original license and requesting a replacement copy.

Captain Hughes said the trooper also obtained identification from the other three men in the car, then called for a motor vehicle check on Mr. Pilius and records checks on all the occupants.

Informed that Mr. Pilius was a 37-year-old white male, the trooper asked Mr. Carter if he knew that the MVA had him listed as white, police said. Mr. Carter said he had no knowledge of this but that he would correct the problem.

Later during the 30-minute-long traffic check, the trooper was informed that Mr. Pilius had been listed by the Baltimore County Police Department's Woodlawn Precinct as an involuntary missing person. When the trooper asked Mr. Carter about this, the suspect replied that his wife often reported him missing when he didn't come home for a couple of days, Captain Hughes said.

At that point, the trooper spoke with Sgt. Lloyd Russell, the duty sergeant at her barracks, who tried to call the Baltimore County department's central records division, to no avail. The sergeant then called the Woodlawn barracks.

Captain Hughes said a lengthy conversation then ensued by radio between the trooper and her sergeant, who talked with an officer at the Woodlawn precinct station. The officer at Woodlawn confirmed that Mr. Pilius had been reported missing by his wife.

Asked by the duty sergeant whether Mr. Pilius was white or black, the Woodlawn officer responded that he was white. The sergeant replied that his trooper had stopped a black motorist, and the Woodlawn officer explained that the missing-person's report was for a white male, officials said.

At that point, the duty sergeant instructed Trooper Fuller to let the motorist go, Captain Hughes said. Privately, State Police officials defended the decision by noting that road troopers often find during motor vehicle checks that information such as race and age are incorrect in motor vehicle records.

E. Jay Miller, spokesman for the Baltimore County Police Department, confirmed last night that a state trooper did contact the Woodlawn station regarding the missing-person report.

"A trooper made the call, and said the person stopped was black," Mr. Miller said. "Our desk person told him that our guy was white, and the trooper said he'd get back to us."

State Police apparently never called back, however.

Only a day earlier, state troopers at Baltimore-Washington International Airport were called to the airport's Budget car rental desk, where Mr. Carter had tried to rent a car using Mr. Pilius' identification.

A suspicious Budget employee, noticing the age discrepancy, called police, but when troopers arrived, Mr. Carter became belligerent at being questioned, even threatening legal action, according to Captain Hughes. The troopers allowed Mr. Carter to leave.

State Police said yesterday Mr. Carter had apparently earlier the same day tried to rent another car at a downtown Budget location using Mr. Pilius' American Express card but had been refused because his signature did not match the one on the credit card.