William Foster, 44, was set to go on trial in the 2008 death of Sgt. Timothy Simpson, 46, on Monday.
Instead, Foster pleaded guilty to 3rd degree murder. Judge Jeffrey Minehart sentenced Foster to 19 to 40 years in prison, to begin after he serves at least 7½ years on unrelated Bucks County charges.
Letters read in court Monday on behalf of Simpson's family described him as a loving and compassionate person who always put others first.
Foster expressed remorse and, referring to Simpson, said "He was a giver, I'm a taker."
Simpson's brother, Terry, reacted to the sentencing on Monday.
"His family is satisfied with what he got," said Terry, also a Philadelphia police officer.
Foster, fleeing police in a stolen car, slammed into Simpson's cruiser as he was responding to a robbery call.
Wanted in Bucks County at the time, Foster had been stopped by Philadelphia police two weeks earlier for carrying a shotgun. An apparent computer problem allowed him to go free, but now we'll be away for a long time.
"He got what he deserved. It's just - we'll never replace what we lost," said Commissioner Charles Ramsey.
Foster has a record of 29 convictions and also an arrest in New Jersey. His driver's license had been suspended for about a decade.
"Never once in all those times - he was given breaks with probation and parole - did he take advantage of anything he was given," said Assistant D.A. Gail Fairman.
Simpson was one of four Philadelphia police officers killed in the line of duty in 2008.