One name often linked to the disappearance of Sherri Miller and Pam Jackson is David Lykken. Lykken was 16 years old when the two girls disappeared and is now serving more than 200 years in prison for unrelated crimes.
Lykken raped and robbed a woman in 1983, but only admitted to burglary in a plea bargain. He was released in 1989 and back in trouble with the law in 1990. That's when he stopped an ex-girlfriend on a road, took her to her Vermillion apartment and raped her repeatedly with her children in the next room.
Lykken was convicted on that crime. The judge considered his criminal history and sentenced him to 227 years in prison.
In 2004, cold case investigators searched the Lykken family farm and called Lykken a person of interest in the 1971 disappearance of Miller and Jackson. Investigators say that search turned up bone fragments, a woman's purse and rubber gloves, among other items.
In 2007, Lykken was charged with murdering Miller and Jackson. Investigators presented a recording from jailhouse informant Aloysius Black Crow who claimed he'd taped Lykken confessing to the crime. But the voice on the tape didn't match Lykken. Black Crow was later found guilty of lying under oath.
"He looked everyone in the eye, in that courtroom, my client, the family of the Jacksons and the Millers and the family of David Lykken and perjured himself," defense attorney Mike Butler said, on February 22, 2008.
Murder charges against Lykken were dropped in February 2008.
The now 59-year-old remains in prison on the prior rape conviction.
Investigators also searched a northwest Iowa gravel pit in 2004 in connection with the cold case. That pit is just across the state line from the Alcester area where Lykken grew up.