A Lego toy brick has helped Utah police crack a 23-year-old cold case, Fox 13 reported.

Police recovered some Legos while investigating the 1991 murder of 78-year-old Lucille Johnson, who was bludgeoned inside her Holladay, Utah, home.

The Legos seemed unimportant at the time, but now have become key evidence in the case against John Sansing, who has been charged in Johnson’s murder. Sansing, 47, is currently on death row in Arizona for a 1998 murder.

“While in that home, it is clear Mr. Sansing bludgeoned Lucille to death, leaving his 5-year-old apparently in the living room to play with Legos. On those Legos were the fingerprints of Mr. Sansing’s juvenile son,” Salt Lake County Sheriff Jim Winder said at a news conference last week, Fox 13 reported.

Police say there is no known motive for the murder, although some jewelry was missing from the home.

Shirley England, Johnson’s daughter, told the station she believes Sansing used his own son to get into her mother’s home. She said she does not think her mother knew him.

“He had a child with him. He probably had some kind of story; I’m just speculating,” she told Fox 13.

Prosecutors are expected to extradite Sansing to Utah to face the murder charge, and police say they are looking at him in connection with other unsolved murders.

“It’s not outside the realm of possibility,” said Sgt. Mike Ikemiyashir, the detective who worked the Johnson murder. “We know there’s similar homicides that occurred in that time frame, 1989 to 1991. So he’s definitely someone we’re looking at.”

Click for the story from Fox 13.