Houston police Chief Art Acevedo says his department has finished its criminal investigation into a deadly January drug raid that killed a couple and injured five officers.

Acevedo said Wednesday that the probe's results have been turned over to the Harris County district's attorney's office. He declined to comment on the investigation's findings.

District Attorney Kim Ogg says her office is still investigating the matter and that all evidence ultimately will be presented to a grand jury.

During the Jan. 28 raid, 59-year-old Dennis Tuttle and his 58-year-old Rhogena Nicholas were fatally shot after officers entered their home.

Police alleged that the couple was selling heroin. But the raid came under scrutiny after allegations that an officer lied in order to obtain the search warrant.