One 17-year-old Lancaster County girl was shot by a suicidal boyfriend, while another died from an injected overdose of heroin.

A 90-year-old woman died after a young man came into her Earl Township home and robbed her at gunpoint, while a city man was stabbed to death during a robbery in his Hershey Avenue home. A different robber was shot and killed during a hold-up attempt in Manheim.

Three others were killed during the past year in crimes of passion, police said, including the well-publicized case of Jan Roseboro, who was found dead in July next to her family's backyard pool in Reinholds.

Police charged her husband, Michael, a 41-year-old funeral director, with his wife's death, releasing details and e-mail exchanges from his extra-marital affair.

Four additional homicides in 2008 still remain a mystery, with no arrests by police.

The dozen homicides during the year that's coming to an end is exactly the same number that occurred in 2007 and is about the average number for Lancaster County, according to newspaper records.

The deaths during 2008, according to accounts at the time, were:

In March, Mae Marie Davis, 17, of New Providence, was shot to death by her boyfriend, 17-year-old Michael Hollow, who state police said then turned the gun on himself. The young couple were heard arguing inside Hollow's New Providence mobile home shortly before they were found.

In April, James J. Kerek, 57, was found stabbed to death in his Hershey Avenue home, killed during the course of a robbery, police said. Another man, Steve Clayton, 39, was charged with the death after detectives said he allegedly confessed to two of his girlfriends. Charges against Clayton are still pending.

Ninety-year-old Anna M. Sensenig died of a heart attack, the result, police believe, of a home-invasion robbery at her home in June. The man who investigators believe committed the crime, Travis Meints, 21, Terre Hill, later killed himself, police said.

The situation was reversed the following month, police said, after Kevin Lee Smith, 19, of Lancaster, along with a friend, tried to rob a man going to work in Manheim. But instead of handing over his money, police said, the employee pulled out his own gun and shot Smith in the stomach.

 The district attorney called the shooting death justifiable homicide. Smith's accomplice has never been charged.

Friends and family of 45-year-old Jan E. Roseboro were shocked by the mother-of-four's unexpected death last July.

Days later, after Roseboro's husband, Michael, was arrested, police said the woman Roseboro had been seeing told them that she and Roseboro had sex hours before Jan Roseboro was killed and had discussed wedding plans.

In September, another 17-year-old Lancaster County girl was found dead.

Police said the teenager, Michelle DeHart, a Manheim Central High School senior from Penn Township, died from an overdose of heroin injected by a 16-year-old boy.

Under Pennsylvania law, someone can be charged with involuntary manslaughter when "as a direct result of the doing of an unlawful act in a reckless or grossly negligent manner ... he causes the death of another person."

Police said the law still applies even though in this case DeHart gave the teenager permission to inject her with heroin. The 16-year-old boy, who was not identified because of his age, was charged as a juvenile with involuntary manslaughter and delivery of heroin.

 In October, Barry Moore Jr., 38, of Manheim, was stabbed to death inside an East Lampeter Township home after police said he and another man, Timothy Lagrone, 25, of 2001 Pine Drive, got into a physical altercation over a woman.

Another domestic dispute in November resulted in the death of 28-year-old Tonya Fetrow of Lancaster, who police said was brutally beaten to death by an ex-boyfriend, Kenneth Brown Jr., 29, Philadelphia, who then dumped her body along a road in East Donegal Township.

The deaths of four other men, all killed in Lancaster City, remain unsolved.

Jose A. Diaz, 35, of Manor Township, was found shot to death multiple times in a parking lot on Clark Street in December. Police said they believe the shooting was not random, and that Diaz was "targeted," because it was known he intended to go the location that night.

Samuel E. Bair, 26, of the 700 block of Prince Street, died of gunshot wounds in August. Police said he was still alive when they found him, but he refused to identify his assailant before he died. Investigators believe the shooting was over a dispute between two groups.

Curtis Charles Howard, 19, of Pittsburgh, was found shot to death on Penn Avenue at Green Street, in July. Investigators learned he had some sort of verbal dispute with other men before he died.

Juan Marquez, 42, Lancaster, was found shot to death in March in a parking lot in the 200 block of West King Street. Police have said only that they believed the shooting, that left a second man seriously wounded, was the result of a verbal dispute.