PHILADELPHIA — Authorities say more charges are likely to be filed in the case of a Philadelphia man accused of barricading himself inside a city row house and shooting six police officers during an hours long standoff last week.

But Philadelphia District Attorney Larry Krasner also warned Monday that the investigation into the “factually complicated case” could take months to complete due to the extensive amount of evidence that must be reviewed.

The alleged shooter, 36-year-old Maurice Hill, is charged with attempted murder, assault and numerous other counts. He’s accused of shooting at officers who were serving a drug warrant Wednesday, then keeping police at bay while he fired repeatedly from inside a building.