New Haven police officers handed out candy and offered trick-or-treating safety tips at the Foxon Boulevard Wal-Mart on Saturday as part of the New Haven Police Department’s Explorers program, a career-education program for young men and women. It was the NHPD’s second year hosting the event, said Chris Senior, a New Haven police officer who remained with the Explorers throughout the day. He said Wal-Mart is an effective place to reach out to families before they hit the streets in their costumes. Still, many parents had already decided the streets of New Haven would be too dangerous for their children Halloween night. Maria Perez, 51, who lives on Front Street, said she thinks the area is unsafe for children at night. Perez said she decided to have a small party at home instead of taking her children trick-or-treating, but appreciated the police presence at the superstore nonetheless.