Lots of coyotes living in the suburbs but you don't hear of them killing deer. Plenty of other food sources such as possums, feral cats, muskrats and an occasional pet dog.
You don't hear any accounts of them roaming in packs but rather just solitary sightings. A couple weeks ago a friend who lives in Warren said he saw a female with two pups behind his house on the other side of his fence that borders a wooded area.
Coyotes get some deer around here, according to the County Ag people.
From Google wiki, in accord with your friend's report:
Although coyotes live in family groups, they usually travel and hunt alone or in loose pairs. In this way they are different from wolves, which sometimes leads to the impression that coyotes do not form packs since they are usually seen alone.
Wolves, now, there you have another--and murderous--cup of tea.