WATERVILLE — For more than 50 years, major crimes in Maine have come under the scrutiny of a special agency within the state police.

“Name any major case that state police have been involved in, and the … Major Crimes Unit has been involved in it,” said Department of Public Safety Spokesman Steve McCausland.

Now, the Major Crimes Unit has turned its focus on Ayla Reynolds, a 21-month-old girl who was reported missing Dec. 17.

The unit took the lead role in the investigation on Dec. 30, almost two weeks after Ayla was last seen. That same day, Waterville Police Chief Joseph Massey announced that foul play was suspected in the toddler’s disappearance.

McCausland offered no new developments Wednesday on the criminal investigation, but said detectives are still at work.

There are three reasons for the Maine State Police Major Crimes Unit to get involved in an investigation. The unit handles homicides, suspicious deaths and major investigations, McCausland said.

“If there is a homicide, we intervene immediately,” he said. “The division investigates all homicides in Maine, with the exceptions of Bangor and Portland. The detectives within those two municipal police departments investigate their own.

“Or, many times, the medical examiner or the attorney general’s office may ask for the Major Crimes Unit to assist in an investigation. In the absence of that, (the unit’s involvement) is usually at the request of local police departments.”

“Major Crimes Unit” is a new name for a decades-old institution, McCausland said. The group, which formed in the mid-1950s, used to be called the Criminal Investigation Division, or CID.

“A decision was made a few months back to change (the name) to the Major Crimes Unit, which is more in line with its task,” McCausland said. “The detectives remain the same. The command of the two divisions remain the same. All that changed was the name to better reflect this day and age of their mission.”

The name change became official Sunday, two days after the name was first introduced to the public by Waterville Police.

“It was coincidental that the name change was announced in conjunction with the Ayla Reynolds investigation,” McCausland said.

The 33 detectives in the unit, which has two divisions, is led by Maj. Gary Wright.

A division led by Lt. Christopher Coleman handles cases in the central and northern part of the state. The other division, led by Lt. Brian McDonough, handles cases in southern Maine.

Coleman’s division, which is overseeing the Ayla Reynolds case, has 18 detectives and three sergeants covering Aroostook, Hancock, Kennebec, Knox, Lincoln, Penobscot, Piscataquis, Sagadahoc, Somerset, Waldo and Washington counties.

Detectives from the southern division have been working on the case as well, McCausland said.

McCausland declined to comment on what advantages the unit might have over municipal police, but said the unit belongs to the largest police agency in the state.

State police assets include a crime laboratory in Augusta, a mobile command center, an evidence response team vehicle and more.

Ayla was reported missing from her Violette Avenue home on Dec. 17. She was last seen wearing green one-piece pajamas with the words “Daddy’s Princess” printed on them. A $30,000 reward has been offered for information that leads investigators to Ayla, who will be two on April 4.

Ben McCanna — 861-9239

bmccanna@centralmaine.com