The Yellowstone County sheriff's office in Billings is investigating the Sunday shooting deaths of former Butte resident Marlene E. (Sandlin) Mazzola, 42, and George Heinrich, 59, a retired Billings area rancher.

      Details were sketchy Monday about the killings.   All Sheriff Richard Schaffer of Billings would say is that the murders appeared to have been "execution type".   He would not elaborate.

      The couple was found in Heinrich's home on U.S. 10 East of Billings, Schaffer said.   He said Heinrich's daughter, who reportedly lived with their father, found the bodies about 4:28 p.m. Sunday.   She notified a male neighbor, who entered the home and then called police.

      Shaffer said he would not release any information about the time of the deaths, type of weapon used or the direction of the investigation.   "It's an old policy of mine since I was chief of detectives" Shaffer said.   " The less information that gets released, the better chance we have of solving the crime.   Also there are a lot of kooks who will come in and cop out to a crime.   Sometimes we have a hard time not arresting them."

      Mrs. Mazzola's Billings address was 2114 Lewis.   Butte police said Monday that autopsies were being conducted in Billings, and that officers here were investigating local angles.   But, local officers said, the Billings authorities weren't releasing any information, even to the Butte police.   Shaffer said the autopsie results weren't available Monday.

      Mrs. Mazzola had known Heinrich about three weeks, Butte friends reported.  

      Mrs. Mazzola, the daughter of the late Robert Sandlin and Lillian Sandlin of Butte, was born here March 16, 1938.   She attended local schools and graduated from Butte High in 1956.   She lived in Billings 12 years before returning to the Mining City.

      She was married to John Mazzola Aug. 16, 1974.   She worked at the Candy Calliope in the Butte Plaza until about 1973, when she went to work for the Butte Chamber of Commerce.   She moved to Billings in July 1979 and became a district supervisor for Avon Products.

      Survivors include her husband John of Butte;   daughters, Janet Tahija of Missoula, and Karen and Julie Tahija of Billings;   mother, Lillian Sandlin of Butte;   brothers, Ed and Frank Shone of Butte, Robert Shone of San Francisco and Cleo Sandlin of Helena;   and sister, Mrs. Jack (Ruth) Linduska of Dillon.

      Services will be announced from Duggan Merrill Dolan Mortuary.