AUGUSTA — State police and the Maine Attorney General’s Office will in the next few weeks begin preparations for the launch in October of the state’s first detective squad dedicated to old and unsolved homicides, officials said Monday.

LD-1121, the law the Legislature passed earlier this month that funded the three-member squad, goes into effect by law in 90 days after the beginning of the new fiscal year, on Oct. 1. Officials plan to have the squad’s members selected by then, said Col. Robert A. Williams, chief of Maine State Police.

“It can’t come soon enough,” said Rep. Karl Ward, R-Dedham, who submitted the bill in December seeking what eventually became $491,662 annually to fund two state police detective positions and a forensic chemist, plus startup costs. “We are thrilled that it is going to become a reality. I can’t wait to get that call that says we solved our first cold case.”

Ward commemorated the passage of the law by visiting Pamela McLain, whose daughter Joyce’s body was discovered near Schenck High School of East Millinocket on Aug. 10, 1980, two days after the 16-year-old high school sophomore disappeared while jogging.

Ward gave a cold-case squad t-shirt to McLain, whose daughter’s case spurred volunteers to start pushing for a squad in 2013.

Seventy cold cases were listed at maine.gov on Monday. Twenty to 25 homicides occur annually in Maine. The Maine attorney general’s office, which prosecutes homicides, has an assistant attorney general handling cold cases, but state police work them when they have time, officials have said.

Squad members will be selected from within Maine State Police, said Steve McCausland, spokesman for the Maine Department of Public Safety. State police will continue to work cold cases like they have in the past until then.

“It is not like everything has been halted waiting for the establishment of this team. We have had tremendous success over the years with a number of cases and we will continue to do so,” McCausland said.

Patrick Day, a volunteer who helped legislators get the case created, doubted that the formation of the squad would lead to false hopes being created among cold-case victims’ family members.

“I think everybody is realistic,” Day said Monday. “If these cases could have been solved easily they would have, but situations change, relationships change, so people might be willing to talk so maybe they will discuss information that they weren’t willing to before.”

The groundswell of public support for the squad has stirred a lot of positive talk, Day said.

“Even families that have cases that were previously viewed as non-homicides are asking them to be reviewed to see if mistakes were made,” Day said. “People are coming out of the woodwork because they want help.”