A district judge arraigned 46-year-old George Hitcho Jr. early Friday morning and ordered him to Northampton County Prison.
Authorities say Hitcho shot Freemansburg police Officer Robert Lasso Thursday afternoon when the officer arrived at his home to respond to a domestic dispute report. Lasso was pronounced dead at a hospital.
A shotgun police believe was used in the killing was recovered at the scene.
Court documents show Lasso had previously arrested Hitcho in a case that ended with Hitcho pleading guilty to a drug paraphernalia charge in 2007.
Officials say Lasso was married with two young children, ages 5 and 3. His father is a Freemansburg borough councilman.
Action News was there as a police motorcade escorted the hearse carrying Lasso's body left the hospital. Lasso was a 7-year veteran of the Borough of Freemansburg Police Department.
He is said to be the first officer killed in the line of duty in that department.
"Officer Lasso was a dedicated police officer and a family man, married and a father of two small children, and tonight we grieve," Northampton County District Attorney John Morganelli said during a press conference.
Authorities say it was about 5:06 p.m. that Officer Lasso was responding to a report of a disturbance in the 400 block of New Street.
Police say while investigating the disturbance at 444 New Street Hitcho shot Officer Lasso in the head with a shotgun.
So far, authorities say the specifics are unclear.
"We want to be able to make sure we have an accurate timeline of where the police officer responded to, what happened, and where he is going and why he was going," Morganelli said.
Lasso was later pronounced dead at St. Luke's Hospital in Bethlehem.
"We do have our major case team called out; we have members from many stations gathering information, gathering facts and evidence and putting this together," Captain William Tepper said.
No other suspects are being sought in connection with the fatal shooting.
The Associated Press contributed to this report.