Stymied by several puzzling killings this year, the Baltimore County Police Department's homicide unit is on pace for its lowest homicide clearance rate in six years.
Detectives have solved two-thirds of the 21 homicides reported this year in the county.
But they have been unable to determine who is responsible for two strangling deaths and one fatal stabbing - all involving women - or who shot two men at an Owings Mills apartment complex.
Two other homicides - one in which a man was shot while sitting in his car outside his Milford Mill apartment, the other involving an Essex man shot in front his home - also remain unsolved.
Since the mid-1990s, when police Chief Terrence B. Sheridan was hired, the homicide clearance rate has shown an overall increase.
However, homicide detectives have been able to solve only 66 percent of reported homicides this year, compared to 91 percent last year, 80 percent in 1999 and 95 percent in 1998.
Police departments nationwide solve an average of 69 percent of all homicides each year, according to statistics supplied to the FBI.
Baltimore County has averaged about 30 homicides a year for the past two decades. The relatively low number of killings this year means detectives must solve nearly all of them to achieve a high clearance rate.
Bill Toohey, a department spokesman, said detectives have been hampered by several difficult cases this year. He said the lower clearance rate is not a reflection of detectives' investigative skills.
Detectives are having a particularly hard time solving three cases involving female victims, Toohey said.
Gomti Rasik Patel, 44, was found strangled and beaten in her apartment in the 3100 block of Wallford Drive in Dundalk on Jan. 20.
Edwina Delores Arnett, 70, was found strangled and beaten in the courtyard of her apartment building in the 2100 block of Dundalk Ave. on June 23.
Toohey said detectives have developed few leads.
"One of the problems is these crimes seem to have happened in off hours when there were not a lot of witnesses moving around," Toohey said.
There was no sign of forced entry in either case, indicating that the women may have known their attackers, Toohey said. That is one reason police do not believe the two cases - and an unsolved strangling of another Dundalk woman last year - are related.
"I can say with great confidence, we have no evidence that someone is targeting women in Dundalk," Toohey said.
"In all of these cases, it appears the women may have known their murderers, spoken to their murderers, and let them into their property," he said.
Toohey said similar circumstances might have led to the death in March of 46-year-old Mary L. Roe, who was stabbed inside the dry cleaning business she managed on Walker Avenue just north of the city line.
The owner of the business said that money also was stolen. But police have refused to say whether robbery was a motive, and there was no sign of forced entry.
Police are also continuing their investigation into the killings of two Bronx, N.Y., men Aug. 20 in the parking lot of the Red Run Apartments in the New Town neighborhood of Owings Mills.
Dwayne Thomas, 31, and Karon Russell Clarrett, 28, were shot while sitting in a car. Police said the two men apparently were targeted and the attack appeared drug-related.
"In an organized killing, the killers often know how to make the trail harder," Toohey said. "You need evidence, you need witnesses and we have not gotten enough of that together yet to solve this case."
Unless some of the cases are solved, the homicide unit will end the year with the lowest clearance rate since 1995, when it solved 66 percent of the 38 homicides reported.
Toohey said the department has had above-average clearance rates recently because county residents have cooperated with investigators.
"One of the things that became evident is the amount of cooperation this agency gets from the public," Toohey said.
"People who know things do come forward and give us trails to follow, but if it happens inside an apartment where no one may have seen anything, it makes things difficult."