A 2-year-old Portland girl is beaten to death. A young woman is asphyxiated in her South Portland apartment. A great-grandmother is killed in her Kittery home. A Scarborough woman disappears for more than a year before her remains are found.

The four homicides have one common characteristic: The killer in each is still free.

Unsolved killings frustrate investigators and torment relatives of the victims, who fear they won’t get justice.

As each day passes, police say, the prospect of solving a homicide decreases. Investigators always hope to gather enough evidence for an arrest within 48 hours of the discovery of the crime.

“That’s the time when you’re going to get the freshest, purest information, ” said Capt. Charles Love, who heads the criminal investigative division of the Maine State Police. His detectives with help from local police are investigating three of the four killings in Maine that have gone unsolved from January 1993 through last month.

Police say none of the cases is closed. In at least two, investigators are working full time.

But, given time, suspects can leave the area, come up with alibis that hold up under questioning, or contact lawyers who tell them not to say anything, Love and others say.

And a victim’s friends, relatives and neighbors can start talking among themselves about what happened. Police say their information isn’t as useful when it has become influenced by perceptions, suspicions and rumors.

Generally, two to three killings go unsolved each year in Maine. That’s better than the national average, officials say.

But the statistics don’t matter to a relative waiting for an arrest. The mother of Susan Hannah of Scarborough is satisfied with the investigation of her daughter’s death, but fears the killer may never be caught.

Caroline Chamberlin says she thinks about Susan every day.

TOO MUCH TIME PASSES

Susan Hannah, 22, had been missing for almost 19 months when her remains were found by a hunter in Limington on Nov. 13, 1993.

Five months after her death was confirmed as a homicide, state police still won’t say how she was killed. They believe she died around the time of her disappearance, April 18, 1992.

Hannah was unemployed and had filed for divorce from her husband, John K. Hannah, shortly before that day when she told her mother she was going for a walk on the beach and would be back for dinner.

Acquaintances reported seeing Hannah on the evening of April 18 at bars in South Portland and Old Orchard Beach. Police aren’t sure if the reports are accurate. Love wouldn’t say why police question them.

Love said the biggest problem in the case “was the year and seven months’ time lapse between her disappearance and the finding of her body.”

It gave investigators two strategic blows.

First, too much time had elapsed for police and experts to determine whether Hannah was killed in the woods or killed in another place and dumped there, Love said.

Knowing where she was killed could lead police to other places to search for more evidence. Little meaningful evidence was gathered in the woods where she was found because so much time had passed, Love said.

The time lapse also meant that investigators were questioning people about Hannah’s death long after it had happened.

“During that time, the person or people involved may have had time to put their stories together and arrange their alibis, ” Love said.

Investigators have interviewed Hannah’s husband at least four times. Love wouldn’t say why: “You can make any conclusion you want.”

John Hannah has repeatedly said he knows nothing about Susan’s disappearance and death.

One of the police interviews with Hannah was conducted Oct. 7 on the pier at Camp Ellis in Saco, as divers working for state police searched the ocean bottom and gathered items in evidence bags that were brought ashore.

Love refused to say if those activities related to the Hannah case, but he did say the search “did not develop any meaningful leads” for any case.

Chamberlin, Hannah’s mother, finds strength in her faith.

“Maybe an arrest will never be made. That’s crossed my mind. But even if an arrest is never made, I feel God’s punishment will be there, ” she said.

ALL BASES COVERED

Maxine Bitomski, 73, of Kittery was an “easy target” for the person who killed her, Love said.

The retired purchasing agent had lived alone in her home on quiet Colonial Road since 1984, when her husband died. Neighbors described her as a tiny, frail woman who needed oxygen or some sort of medical apparatus to help her breathe.

She was last seen alive on the night of Jan. 15, 1993, when a granddaughter visited to check on her. She was found dead in her bathroom the next day by a grandson, Christopher Matthews of Portsmouth, N.H.

Her death was declared a homicide the next day, after an autopsy by the state Medical Examiner’s Office.

Police wouldn’t say then how Bitomski died. Fifteen months later, they still refuse to disclose that information, saying publicity could hurt their case.

“The most unusual thing about the case is her age, ” Love said. “Usually a 73-year-old person doesn’t have enemies. And our information is that she kept to herself and got along with people.”

Neighbors have said they didn’t see anything suspicious the weekend Bitomski died. Love said Bitomski didn’t have a lot of money or valuables.

Various pieces of evidence, including hair and skin samples, have been reviewed and analyzed. Investigators have conducted more than 70 interviews with people who knew Bitomski.

“We may have already talked to whoever did it and not known it, ” Love said.

For relatives, the wait has been trying. Candus Simpson, one of Bitomski’s granddaughters, said in January that the family has tried to accept authorities’ silence.

“You have to try real hard not to feel sorry for yourself. When I watch the news and police solve another murder, I find myself talking to the TV, ” she said. “I want to say, `How about us? Help us.’ ”

The case is still assigned to a detective, but Love said investigators have “pretty much covered their bases.”

“I certainly don’t want to give the impression that we’ve just put this away, because we haven’t, ” he said, “but we need some new information.”

NO VISIBLE MOTIVE

Tammy Dickson, 22, was found bound and gagged Feb. 20 in her apartment at Cortland Court in South Portland. Her 2-year-old son, Marcus, apparently had been in his crib during the killing and remained there for three days.

An autopsy showed that Dickson was asphyxiated the night of Feb. 17. Love would not say how, nor would he release results of an examination for signs of sexual assault.

Why did someone kill her?

After talking to more than 100 people who knew Dickson, “we don’t have an answer, ” Love said.

Police spent several days searching the apartment. Some of the evidence is still being analyzed, Love said.

Detectives recently assessed results of their investigation at a meeting with prosecutors from the state Attorney General’s Office and Dr. Kristin Sweeney of the state Medical Examiner’s Office, Love said.

The session focused on theories as to what happened and who could have killed Dickson, Love said. Names were eliminated from a suspect list, but others were added.

Love said, “We’ve generated some direction, but I don’t want to be more specific because that could come to a stone wall.”

STILL AWAITING TEST RESULTS

Sarina Towle, 2, died sometime after 11 p.m. on March 24. Her bruised body was found at 9 a.m. the next morning by her mother, Loralee Meserve, in Meserve’s apartment in Portland’s West End. Police say the child was beaten to death and sexually assaulted.

Twenty-three days later, police have made no arrests and won’t say if they have suspects.

Meserve and her boyfriend, Carl Bickham, have told police they don’t know how Sarina died. Police won’t say if they think anyone else entered the three-bedroom apartment.

Determining a motive for the killing has been one of the more difficult aspects of the case, said Portland Police Lt. Richard Rizzo.

“When adults are killed there’s often a clear-cut motive for it. But with a 2-year-old child, it’s a little more difficult to pin down, ” he said.

Rizzo said he doesn’t consider the case unsolved, because of the relatively short time since the killing.

He considers homicide cases unsolved when investigators have no leads, or when they have a good idea who the killer is but not enough evidence to make the case stand up in court.

He stressed that investigators are still waiting for results of laboratory tests done on evidence sent to the FBI.

Rizzo said detectives have theories about what happened, but he wouldn’t be specific.

“The longer any homicide investigation goes on, it concerns people like myself, ” he said. “The colder the trail, the more likely it is that a case not this case will be unsolved.”

SEEKING MORE CLUES

It has been 11 days since Raynald Levesque, 55, was found shot to death in his kitchen in Madison. He is Maine’s most recent homicide victim.

A delivery man discovered Levesque’s body after finding no one at his recycling and redemption business next door.

Love, of the state police, said some people have called with information, but police are looking for more.

They are trying to find a man seen outside Levesque’s home around the time he was killed. The man is not a suspect, but police want to question him.

Time is passing, and police are “working very hard” on the case, Love said. “But we haven’t made a lot of progress.”