Authorities said Thursday that the Shakopee couple killed by the man’s son suffered blows to the head just a few hours before the bodies were found in their home.

Police discovered Renee D. Ahrens, 67, and Terry L. Weimer, 68, beaten to death in their house late Monday while the officers were making a welfare check request. The two were engaged to be wed.

Weimer’s son, Adam Weimer, 40, was tracked to his home in Waseca that next day and fatally shot himself during a standoff with police.

The Hennepin County medical examiner’s office also said Thursday that Ahrens and Weimer were killed shortly before 9 p.m. Monday, less than three hours before their bodies were discovered.

The medical examiner’s office said both suffered “craniocerebral injuries.”

Describing the scene inside the couple’s home in the 1100 block of Dakota Street, Police Chief Jeff Tate said, “Brutal is probably a good word.”

Authorities have yet to reveal what may have prompted the killings.

The son has a criminal history — court records show him with convictions for theft, drunken driving and assault. Tate said the son has lived at the couple’s home in the past, and police believe he still had belongings there.

Tate said there have been a “handful” of calls for service at the Shakopee home, but “nothing related to this case.”