Marimow’s series of articles exposed that city police dogs had attacked more than 350 people—often without justification—and led to investigations of the Philadelphia Police Department’s K-9 unit, resulting in the removal of more than a dozen officers.

It was nearly 1 o’clock in the morning last May 31 when an exuberant Matthew Horace bounded up the subway staircase on the east side of City Hall.

Like thousands of others, Horace had come to Center City to celebrate the Sixers’ sweep of the NBA Championship Series. He was looking for a good time. He never found it.

As he stepped out of the stairwell, Horace saw a snarling German shepherd, followed by four or five police officers, moving rapidly toward him. Alarmed, he turned and began walking fast. It was too late. Moments later, Horace was clinging to a traffic light and screaming as Macho, a police K-9 dog, ripped his right sneaker off and sank his teeth repeatedly into Horace’s foot.

Police officer Daniel Bechtel finally pulled the dog off and shouted at Horace to “get the f- out of here,” Horace recalls. Then, as fast as they had appeared, Bechtel and the dog disappeared into the crowd. But Matthew Horace was in no shape to go anywhere. After bystanders helped him hobble to 13th and Market Streets, two other police officers drove him to Hahnemann University Hospital. He would remain there for a week.

Matthew Horace, a man with no criminal record, then or now, has plenty of company. A three-month Inquirer investigation has found that a hard core of errant K-9 police officers, and their dogs, is out of control.

Furthermore, the Police Department has made no attempt to hold these men, or their colleagues, to any sort of written guidelines or standard procedures spelling out when to attack and when to hold back.

Nor has the department shown any interest in monitoring the performance of its 125-man K-9 unit or trying to keep track of unjustified attacks by dogs.

The problem is severe enough that Anthony Taff, the man who founded the Philadelphia K-9 unit 22 years ago, disavows the manner in which the dogs are currently trained. He also believes that a small but significant minority of officers are failing to contain their dogs or are commanding them to attack and maul citizens needlessly.