A Brooklyn Park man charged in juvenile court for the brutal 2015 murder of north Minneapolis activist and artist Susan Spiller was certified Wednesday to stand trial as an adult in her killing.

Demetrius A. Wynne, who turns 19 Thursday, was 14 when he allegedly killed Spiller in her home in the 5100 block of N. Dupont Avenue sometime between late July 15 and early July 16, 2015. He is charged with one count of second-degree murder with intent and one count of second-degree murder without intent.

Spiller, 68, was strangled, beaten and stabbed several times. Her cause of death was determined to be "complex homicidal violence."

Authorities matched a fingerprint from the crime scene to Wynne and found his DNA on a fingernail clipping taken from Spiller's right hand, the charges said.

Wynne's attorney, Mike Padden, declined to comment. Wynne's first appearance is scheduled for 1:30 p.m. Thursday.

Hennepin County Attorney Mike Freeman issued a written statement saying adult certification was the right call by Hennepin County District Judge Tanya Bransford. Wynne faced up to two years' probation in juvenile court for the offense. Second-degree murder in adult court is punishable by up to 40 years in prison.

"This was a home burglary and brutal killing and by no stretch of the imagination would two years be sufficient for either punishment or rehabilitation," Freeman said in a written statement. "Now we will focus on proving Mr. Wynne guilty beyond a reasonable doubt."

According to the criminal complaint: Spiller had "ongoing issues" with neighbors in a home where Wynne lived at the time.

She was last seen walking her dog between 8:30 p.m. and 9 p.m. on July 15. Cellphone records showed that she made two 911 calls that evening about children next door taking the meter off a fire hydrant.

Police responded to her home about 8:50 a.m. on July 16 after Spiller's son stopped by to drop off his child for day care. He called police after Spiller didn't answer her door or phone, and after he saw an open window in the back of the home.

Police found Spiller dead in her bedroom. She was lying partly on the bed and a large amount of dried blood was on the sheets and floor, the charges said.

Spiller suffered "significant" injury to her jaw, which was broken, and had finger impressions on her neck.

No items of value were taken from Spiller's home, and there was no record of anyone using her credit cards.

Police canvassing the neighborhood that morning spoke to Wynne's mother, and Wynne identified himself to police, according to the complaint. Wynne and his brother allegedly told police they slept with the window open that night and did not hear any screams or disturbances.

Authorities received a break in the case last June when Wynne was arrested in Hennepin County on suspicion of threatening someone with what turned out to be a pellet gun. As an adult, his fingerprints were entered into a statewide database and a match was made with a print from the kitchen window in the back of Spiller's home.

Wynne allegedly told police last June that he had not been inside Spiller's house, did not know her and never hung out in the neighborhood, the charges said. His family moved from the neighborhood soon after her death.

A judge heard arguments in September about the adult certification and received additional written comments.

Sara Sandhofer, a Hennepin County probation officer, testified in September that the case should be moved to adult court because the killing happened in Spiller's home, was carried out in a particularly gruesome manner and Spiller's age and slight stature made her vulnerable.

"She wouldn't have been a match for many people," she said.