A northern Illinois man charged with killing four people and injuring seven others by stabbing, beating and driving over them has been denied pretrial release.

A judge in the city of Rockford ruled Tuesday that Christian Soto must remain in jail pending trial. The judge scheduled an April 15 arraignment for the 22-year-old.

The Associated Press left a message Tuesday seeking comment from an attorney listed in court records as representing Soto. A woman who identified herself as Soto’s sister last week declined to comment to the AP.

Authorities have said Soto was behind a series of frenzied attacks Wednesday at multiple addresses in a Rockford neighborhood, but said they have not determined a motive.

The Winnebago County coroner identified those killed as 63-year-old Romona Schupbach; 23-year-old Jacob Schupbach; 49-year-old Jay Larson; and 15-year-old Jenna Newcomb.

Winnebago County State’s Attorney J. Hanley said Soto told police after his arrest that he had smoked marijuana with Jacob Schupbach and believed the drugs "were laced with an unknown narcotic" that made him paranoid.

Authorities said Soto first fatally stabbed Schupbach and his mother, then he beat, stabbed and used a truck to run over Larson, who was working as a mail carrier. He next wounded three people inside one home, and beat Newcomb, her sister and a friend with a baseball bat inside another home. The attacks happened within a matter of minutes.

Authorities said Winnebago County sheriff deputies arrested Soto as he fled from another home where he had stabbed a woman but had been slowed down by a driver who stopped to intervene.