Fairfax County police are looking for an acquaintance of a 30-year-old man found dead outside an Alexandria home about 2 a.m. Sunday, police said.

Mark Earl Ives, of Alexandria, was found dead outside a home in the 5400 block of Broadmoor Street after police responded to a call for an “unknown situation,” Fairfax police spokesman Eddy Azcarate said.

Ives had been assaulted by a man he knew and died from injuries to his upper body, Azcarate said. An autopsy will determine the cause and manner of death, he said.

“We’re not sure if a weapon was involved or if it was fists or feet,” Azcarate said.

He said no one has been charged but that police are looking for the acquaintance, whose name was not released. Police also did not release an address for Ives, but Azcarate said he lived in the same area where he was killed, which is along Telegraph Road in the Alexandria section of Fairfax County south of the Beltway.

Neighbors in the Hayfield Farm subdivision, where Halloween decorations and freshly planted yellow and maroon mums filled the neatly manicured yards of Colonial and split-level homes, said Ives’s girlfriend lived across the street from the house where he collapsed on the front step. A trail of blood stretched down the street, they said.

No one answered the door at the two-story Colonial where neighbors said Ives’s girlfriend lived.