(CNN) -- A New Jersey man is accused of killing a 6-year-old boy and seriously wounding the boy's 12-year-old sister, Jason Laughlin of the Camden County Prosecutor's Office said Monday.
Osvaldo Rivera, 31, was arrested Sunday afternoon and charged with murder and attempted murder, the prosecutor's office said in a news release.
Dominick Andujar was found dead with his throat slit in a home in the city of Camden, officials said. His sister suffered stab wounds and fled to a neighbor's home after the attack. She is in critical condition at Cooper Hospital in Camden.
Investigators said Rivera, who lives in the area and goes by the nickname "Popeye," was discovered in an apartment on the north side of the city, hiding between a mattress and a bedroom wall. He was found with blood-stained sneakers that appeared to match bloody footprints in the victims' home, the prosecutor's office said.
"Several citizens came forward and showed the courage to provide information, which helped lead to the initial apprehension," Camden County Prosecutor's Office Lt. Frank Falco said.
Rivera told investigators he had smoked "wet," a combination of marijuana and PCP, before the killing, the prosecutor's office said.
This marks the second time this drug combination has been connected with the slaying of a child in Camden, the office said. Chevonne Thomas is believed to have been smoking wet prior to allegedly beheading her son, Zahree, on August 22..
Rivera is being held at the Camden County Jail, the prosecutor's office said, and an arraignment is expected Tuesday.
Attempts to contact an attorney for comment were unsuccessful Monday. Laughlin, of the prosecutor's office, said it appeared Rivera did not yet have an attorney.