Police arrested a man Saturday they say killed his girlfriend and two of her children — and wounded another one in a knife attack on Staten Island. 

Investigators say 23-year-old Michael Sykes stabbed  26-year-old Rebecca Cutler and her 4-month-old and 1-year-old daughters to death at the Ramada Inn in Willowbrook Wednesday.

Cops arrested Sykes in Queens at around 4 Saturday afternoon — after a three day manhunt.

They say Cutler had been stabbed more than 40 times, and the girls were stabbed more than five times each.

The victims were pronounced dead at the hospital.

Officials say Cutler's two-year old is in critical condition.

Police say Sykes is the father of the 4-month-old. 

The victims were staying at the hotel as part of the city homeless shelter program.