GRAND RAPIDS, MI -- The "dangerous crew" of five people who allegedly broke into a Veto Street NW home early Monday, carrying out a brutal robbery and assault on college students, likely knew exactly what property they wanted to steal.

That's because they had seen some of it hours earlier.

Grand Rapids police say the suspects attended a party thrown by the college students Sunday night, then came back at 4 a.m. to carry out their criminal plan.

Police talked about that plan today as they announced the arrests of four young men, including a 14-year-old, for the troubling robbery and assault. Police are still looking for a 19-year-old in connection with the case.

Male college students who were sleeping at the home were pistol-whipped and then tied up while a female was sexually assaulted.

Grand Rapids police Capt. Jeff Hertel said several detectives and investigators worked many hours on tips that rolled in from neighbors and even other party-goers about the case.

The tips paid off.

"We have a very dangerous group of individuals here," Hertel said.

"This case has been troubling. It has shaken even our most seasoned investigator in the family services team," he said.

As they continue to investigate, police now think the suspects are responsible for other crimes in Kent County, including church burglaries and other break-ins.

During a press conference today, Hertel described them as a "dangerous crew."

The adults who have been arrested -- Rederick Melton, 20; Dorian Jacqwell Jones, 20; and Brandon Tyrell Towns, 25 -- all are expected to be charged with first-degree criminal sexual conduct, armed robbery and home invasion.

Police did not release the names of those who had been arrested, but jail records show they are lodged in the Kent County Jail in relation to the Veto Street NW case.

Police are still looking for a James Edward Hodges, 19, as the fifth suspect.

Police today credited an intensive investigation by detectives, who put long hours working on the case, with getting it solved.

"It all came together really quite well," he said.

E-mail John Tunison: jtunison@mlive.com and follow him on Twitter at twitter.com/johntunison